Boya Microelectronics
Memory Series
BY25Q64AS
64M BIT SPI NOR FLASH
Features
● Serial Peripheral Interface (SPI)
- Standard SPI: SCLK, /CS, SI, SO, /WP, /HOLD
- Dual SPI: SCLK, /CS, IO0, IO1, /WP, /HOLD
- Quad SPI: SCLK, /CS, IO0, IO1, IO2, IO3
● Read
- Normal Read (Serial): 55MHz clock rate
- Fast Read (Serial): 108MHz clock rate with 30PF load
- Dual I/O data transfer up to 216Mbits/S
- Quad I/O data transfer up to 432Mbits/S
-Continuous Read with 8/16/32/64-byte Wrap
● Program
- Serial-input Page Program up to 256bytes
- Program Suspend and Resume
● Erase
- Block erase (64/32 KB)
- Sector erase (4 KB)
- Chip erase
- Erase Suspend and Resume
● Program/Erase Speed
- Page Program time: 0.6ms typical
- Sector Erase time: 50ms typical
- Block Erase time: 0.15/0.25s typical
- Chip Erase time: 25s typical
● Flexible Architecture
- Sector of 4K-byte
- Block of 32/64K-byte
● Low Power Consumption
- 20mA maximum active current
- 5uA maximum power down current
● Software/Hardware Write Protection
- 3x256-Byte Security Registers with OTP Locks
- Discoverable Parameters (SFDP) register
- Enable/Disable protection with WP Pin
- Write protect all/portion of memory via software
- Top or Bottom, Sector or Block selection
● Single Supply Voltage
- Full voltage range: 2.7~3.6V
● Temperature Range
- Commercial (0℃ to +70℃)
- Industrial (-40℃ to +85℃)
- Industrial (-40℃ to +105℃)
● Cycling Endurance/Data Retention
- Typical 100k Program-Erase cycles on any sector
- Typical 20-year data retention
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Contents
BY25Q64AS
Contents
1. Description ................................................................................. 4
2. Signal Description ...................................................................... 6
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
Input/Output Summary ................................................................................. 6
Chip Select (/CS) .......................................................................................... 6
Serial Clock (SCLK) ..................................................................................... 6
Serial Input (SI)/IO0 ..................................................................................... 6
Serial Data Output (SO)/IO1......................................................................... 7
Write Protect (/WP)/IO2 ............................................................................... 7
HOLD (/HOLD)/IO3 .................................................................................... 7
VCC Power Supply ....................................................................................... 8
VSS Ground .................................................................................................. 8
3. Block/Sector Addresses ............................................................. 9
4. SPI Operation .......................................................................... 10
4.1
4.2
4.3
Standard SPI Instructions ............................................................................ 10
Dual SPI Instructions .................................................................................. 10
Quad SPI Instructions ................................................................................. 10
5. Operation Features ................................................................... 11
5.1
Supply Voltage .............................................................................................11
5.1.1 Operating Supply Voltage .........................................................11
5.1.2 Power-up Conditions ................................................................11
5.1.3 Device Reset ............................................................................11
5.1.4 Power-down .............................................................................11
5.2
Active Power and Standby Power Modes ....................................................11
5.3
Hold Condition............................................................................................ 12
5.4
Status Register............................................................................................. 13
5.4.1 Status Register Table .............................................................. 13
5.4.2 The Status and Control Bits..................................................... 13
5.4.3 Status Register Protect Table .................................................. 15
5.4.4 Write Protect Features............................................................. 15
5.4.5 Status Register Memory Protection ......................................... 16
6. Device Identification ................................................................. 18
7. Instructions Description ............................................................ 19
7.1
Configuration and Status Instructions ......................................................... 22
7.1.1 Write Enable (06H) .................................................................. 22
7.1.2 Write Disable (04H) ................................................................. 22
7.1.3 Read Status Register (05H or 35H or 15H) ............................. 23
7.1.4 Write Status Register (01H or 31H or 11H) ............................. 23
7.1.5 Write Enable for Volatile Status Register (50H) ....................... 24
7.2
Read Instructions......................................................................................... 25
7.2.1 Read Data (03H) ..................................................................... 25
7.2.2 Fast Read (0BH) ..................................................................... 26
7.2.3 Dual Output Fast Read (3BH) ................................................. 27
7.2.4 Quad Output Fast Read (6BH) ................................................ 28
7.2.5 Dual I/O Fast Read (BBH) ....................................................... 29
7.2.6 Quad I/O Fast Read (EBH)...................................................... 31
7.2.7 Quad I/O Word Fast Read (E7H) ............................................ 33
7.2.8 Set Burst with Wrap (77H) ....................................................... 35
7.3
ID and Security Instructions ....................................................................... 36
7.3.1 Read Manufacture ID/ Device ID (90H) ................................... 36
7.3.2 Dual I/O Read Manufacture ID/ Device ID (92H) ..................... 37
7.3.3 Quad I/O Read Manufacture ID/ Device ID (94H) ................... 38
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Contents
BY25Q64AS
7.3.4 Read JEDEC ID (9FH) ............................................................ 39
7.3.5 Read Unique ID Number (4Bh) ............................................... 40
7.3.6 Deep Power-Down (B9H) ........................................................ 41
7.3.7 Release from Deep Power-Down/Read Device ID (ABH) ....... 42
7.3.8 Read Security Registers (48H) ................................................ 43
7.3.9 Erase Security Registers (44H) ............................................... 44
7.3.10 Program Security Registers (42H) ........................................... 45
7.3.11 Enable Reset (66H) and Reset Device (99H) .......................... 46
7.3.12 Read Serial Flash Discoverable Parameter (5AH) .................. 47
7.4
Program and Erase Instructions .................................................................. 52
7.4.1 Page Program (02H) ............................................................... 52
7.4.2 Quad Page Program (32H)...................................................... 53
7.4.3 Fast Page Program (F2H) ....................................................... 54
7.4.4 Sector Erase (20H) .................................................................. 55
7.4.5 32KB Block Erase (52H) ......................................................... 56
7.4.6 64KB Block Erase (D8H) ......................................................... 57
7.4.7 Chip Erase (60/C7H) ............................................................... 58
7.4.8 Erase / Program Suspend (75H) ............................................. 59
7.4.9 Erase / Program Resume (7AH).............................................. 60
8. Electrical Characteristics .......................................................... 61
8.1
8.2
8.3
8.4
8.5
8.6
8.7
Absolute Maximum Ratings ....................................................................... 61
Operating Ranges ........................................................................................ 61
Latch Up Characteristics ............................................................................. 62
Power-up Timing......................................................................................... 62
DC Electrical Characteristics ...................................................................... 63
AC Measurement Conditions ...................................................................... 65
AC Electrical Characteristics ...................................................................... 65
9. Package Information ................................................................ 69
9.1
9.2
9.3
9.4
Package 8-Pin SOP 150-mil ........................................................................ 69
Package 8-Pin SOP 208-mil ........................................................................ 70
Package 8-Pad WSON (6x5mm) ................................................................ 71
Package USON8 (4*3mm).......................................................................... 72
10. Order Information ..................................................................... 73
10.1
10.2
Valid part Numbers and Top Side Marking................................................. 74
Minimum Packing Quantity (MPQ) ........................................................... 75
11. Document Change History ....................................................... 76
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Description
BY25Q64AS
1. Description
The BY25Q64AS is 64M-bit Serial Peripheral Interface (SPI) Flash memory, and supports the
Dual/Quad SPI: Serial Clock, Chip Select, Serial Data I/O0 (SI), I/O1 (SO), I/O2 (/WP), and I/O3
(/HOLD). The Dual I/O data is transferred with speed of 216Mbits/s and the Quad I/O & Quad
output data is transferred with speed of 432Mbits/s. The device uses a single low voltage power
supply, ranging from 2.7 Volt to 3.6 Volt.
Additionally, the device supports JEDEC standard manufacturer and device ID and three
256-bytes Security Registers.
In order to meet environmental requirements, Boya Microelectronics offers 8-pin SOP 208mil,
8-pad WSON 6x5-mm, and other special order packages, please contacts Boya Microelectronics
for ordering information.
Figure 1. Logic diagram
VCC
SCLK
SO
SI
/CS
BY25QXX
/WP
/HOLD
VSS
Figure 2. Pin Configuration SOP8
Top View
Apr
2022
/CS
1
(IO1)SO
2
8
SOP8 208mil
VCC
7
/HOLD(IO3)
(IO2)/WP
3
6
SCLK
VSS
4
5
SI(IO0)
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Description
BY25Q64AS
Figure 3.1. Pin Configuration WSON 5*6mm
/CS
1
(IO1)SO
2
8
VCC
7
/HOLD(IO3)
Top View
(IO2)/WP
3
6
SCLK
VSS
4
5
SI(IO0)
Figure 3.2. Pin Configuration DFN 4*3mm
/CS
1
8
VCC
(IO1)SO
2
7
/HOLD(IO3)
SCLK
Top View
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2022
(IO2)/WP
3
6
VSS
4
5
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SI(IO0)
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Signal Description
BY25Q64AS
2. Signal Description
During all operations, VCC must be held stable and within the specified valid range: VCC (min) to
VCC (max).
All of the input and output signals must be held High or Low (according to voltages of VIH, VOH,
VIL or VOL, see Section 8.6, DC Electrical Characteristics on page 60). These signals are
described next.
2.1 Input/Output Summary
Table 1. Signal Names
Pin Name
I/O
/CS
I
SO (IO1)
I/O
/WP (IO2)
I/O
VSS
Chip Select
Serial Output for single bit data Instructions. IO1 for Dual or Quad
Instructions.
Write Protect in single bit or Dual data Instructions. IO2 in Quad mode.
The signal has an internal pull-up resistor and may be left unconnected
in the host system if not used for Quad Instructions.
Ground
SI (IO0)
I/O
SCLK
I
/HOLD (IO3)
I/O
VCC
Description
Serial Input for single bit data Instructions. IO0 for Dual or Quad
Instructions.
Serial Clock
Hold (pause) serial transfer in single bit or Dual data Instructions. IO3 in
Quad-I/O mode. The signal has an internal pull-up resistor and may be
left unconnected in the host system if not used for Quad Instructions.
Core and I/O Power Supply
2.2 Chip Select (/CS)
The chip select signal indicates when an instruction for the device is in process and the other
signals are relevant for the memory device. When the /CS signal is at the logic high state, the
device is not selected and all input signals are ignored and all output signals are high impedance.
Unless an internal Program, Erase or Write Status Registers embedded operation is in progress,
the device will be in the Standby Power mode. Driving the /CS input to logic low state enables the
device, placing it in the Active Power mode. After Power Up, a falling edge on /CS is required prior
to the start of any instruction.
2.3 Serial Clock (SCLK)
This input signal provides the synchronization reference for the SPI interface. Instructions,
addresses, or data input are latched on the rising edge of the SCLK signal. Data output changes
after the falling edge of SCLK.
2.4 Serial Input (SI)/IO0
This input signal is used to transfer data serially into the device. It receives instructions, addresses,
and data to be programmed. Values are latched on the rising edge of serial SCK clock signal.
SI becomes IO0 an input and output during Dual and Quad Instructions for receiving instructions,
addresses, and data to be programmed (values latched on rising edge of serial SCK clock signal)
as well as shifting out data (on the falling edge of SCK).
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Signal Description
BY25Q64AS
2.5 Serial Data Output (SO)/IO1
This output signal is used to transfer data serially out of the device. Data is shifted out on the
falling edge of the serial SCK clock signal.
SO becomes IO1 an input and output during Dual and Quad Instructions for receiving instructions,
addresses, and data to be programmed (values latched on rising edge of serial SCK clock signal)
as well as shifting out data (on the falling edge of SCK).
2.6 Write Protect (/WP)/IO2
When /WP is driven Low (VIL), while the Status Register Protect bits (SRP1 and SRP0) of the
Status Registers (SR2[0] and SR1[7]) are set to 0 and 1 respectively, it is not possible to write to
the Status Registers. This prevents any alteration of the Status Registers. As a consequence, all
the data bytes in the memory area that are protected by the Block Protect, TB, SEC, and CMP bits
in the status registers, are also hardware protected against data modification while /WP remains
Low. The /WP function is not available when the Quad mode is enabled (QE) in Status Register 2
(SR2[1]=1).
The /WP function is replaced by IO2 for input and output during Quad mode for receiving
addresses, and data to be programmed (values are latched on rising edge of the SCK signal) as
well as shifting out data (on the falling edge of SCK). /WP has an internal pull-up resistance; when
unconnected; /WP is at VIH and may be left unconnected in the host system if not used for Quad
mode.
2.7 HOLD (/HOLD)/IO3
The /HOLD function is only available when QE=0, If QE=1, The /HOLD function is disabled, the pin
acts as dedicated data I/O pin
The /HOLD signal goes low to stop any serial communications with the device, but doesn’t stop
the operation of write status register, programming, or erasing in progress.
The operation of HOLD, need /CS keep low, and starts on falling edge of the /HOLD signal, with
SCLK signal being low (if SCLK is not being low, HOLD operation will not start until SCLK being
low). The HOLD condition ends on rising edge of /HOLD signal with SCLK being low (If SCLK is
not being low, HOLD operation will not end until SCLK being low).
The Hold condition starts on the falling edge of the Hold (/HOLD) signal, provided that this
coincides with SCK being at the logic low state. If the falling edge does not coincide with the SCK
signal being at the logic low state, the Hold condition starts whenever the SCK signal reaches the
logic low state. Taking the /HOLD signal to the logic low state does not terminate any Write,
Program or Erase operation that is currently in progress.
/CS
SCLK
/HOLD
HOLD
HOLD
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Signal Description
BY25Q64AS
2.8 VCC Power Supply
VCC is the supply voltage. It is the single voltage used for all device functions including read,
program, and erase.
2.9 VSS Ground
VSS is the reference for the VCC supply voltage.
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Block/Sector Addresses
BY25Q64AS
3. Block/Sector Addresses
Table 2. Block/Sector Addresses of BY25Q64AS
Memory
Density
Block(64k
byte)
Block(32k
byte)
Half block
0
Block 0
Half block
1
Half block
2
Block 1
Half block
3
64Mbit
：
：
Half block
250
Block 126
Half block
251
Half block
252
Block 127
Half block
253
Sector 0
Sector
Size(KB)
4
000000h-000FFFh
：
：
：
Sector 7
4
007000h-007FFFh
Sector 8
4
008000h-008FFFh
：
4
：
Sector 15
4
00F000h-00FFFFh
Sector 16
4
010000h-010FFFh
：
：
：
Sector 23
4
017000h-017FFFh
Sector 24
4
018000h-018FFFh
：
：
：
Sector 31
4
01F000h-01FFFFh
：
：
：
Sector 2016
4
7E0000h-7E0FFFh
Sector No.
：
Address range
：
：
Sector 2023
4
7E7000h-7E7FFFh
Sector 2024
4
7E8000h-7E8FFFh
：
：
：
Sector 2031
4
7EF000h-7EFFFFh
Sector 2032
4
7F0000h-7F0FFFh
：
：
：
Sector 2039
4
7F7000h-7F7FFFh
Sector 2040
4
3F8000h-3F8FFFh
：
：
：
Sector 2047
4
7FF000h-7FFFFFh
Notes:
1. Block = Uniform Block, and the size is 64K bytes.
2. Half block = Half Uniform Block, and the size is 32k bytes.
3. Sector = Uniform Sector, and the size is 4K bytes.
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SPI Operation
BY25Q64AS
4. SPI Operation
4.1 Standard SPI Instructions
The BY25Q64AS features a serial peripheral interface on 4 signals bus: Serial Clock (SCLK), Chip
Select (/CS), Serial Data Input (SI) and Serial Data Output (SO). Both SPI bus mode 0 and 3 are
supported. Input data is latched on the rising edge of SCLK and data shifts out on the falling edge
of SCLK.
4.2 Dual SPI Instructions
The BY25Q64AS supports Dual SPI operation when using the “Dual Output Fast Read” (3BH),
“Dual I/O Fast Read” (BBH) and “Read Manufacture ID/Device ID Dual I/O” (92H) instructions.
These instructions allow data to be transferred to or from the device at two times the rate of the
standard SPI. When using the Dual SPI instruction the SI and SO pins become bidirectional I/O
pins: IO0 and IO1.
4.3 Quad SPI Instructions
The BY25Q64AS supports Quad SPI operation when using the “Quad Output Fast Read”(6BH),
“Quad I/O Fast Read” (EBH) ,”Quad I/O word Fast Read”(E7H),”Read Manufacture ID/Device ID
Quad I/O”(94H) and “Quad Page Program”(32H) instructions. These instructions allow data to be
transferred to or from the device at four times the rate of the standard SPI. When using the Quad
SPI instruction the SI and SO pins become bidirectional I/O pins: IO0 and IO1, and /WP and
/HOLD pins become IO2 and IO3. Quad SPI instructions require the non-volatile Quad Enable bit
(QE) in Status Register to be set.
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Operation Features
BY25Q64AS
5. Operation Features
5.1 Supply Voltage
5.1.1
Operating Supply Voltage
Prior to selecting the memory and issuing instructions to it, a valid and stable VCC voltage within
the specified [VCC(min), VCC(max)] range must be applied (see operating ranges of page 58). In
order to secure a stable DC supply voltage, it is recommended to decouple the VCC line with a
suitable capacitor (usually of the order of 10nF to 100nF) close to the VCC/VSS package pins.
This voltage must remain stable and valid until the end of the transmission of the instruction and,
for a Write instruction, until the completion of the internal write cycle (tW).
5.1.2
Power-up Conditions
When the power supply is turned on, VCC rises continuously from VSS to VCC. During this time,
the Chip Select (/CS) line is not allowed to float but should follow the VCC voltage, it is therefore
recommended to connect the /CS line to VCC via a suitable pull-up resistor.
In addition, the Chip Select (/CS) input offers a built-in safety feature, as the /CS input is edge
sensitive as well as level sensitive: after power-up, the device does not become selected until a
falling edge has first been detected on Chip Select (/CS). This ensures that Chip Select (/CS) must
have been High, prior to going Low to start the first operation.
5.1.3
Device Reset
In order to prevent inadvertent Write operations during power-up (continuous rise of VCC), a
power on reset (POR) circuit is included. At Power-up, the device does not respond to any
instruction until VCC has reached the power on reset threshold voltage (this threshold is lower
than the minimum VCC operating voltage defined in operating ranges of page 58).
When VCC has passed the POR threshold, the device is reset.
5.1.4
Power-down
At Power-down (continuous decrease in VCC), as soon as VCC drops from the normal operating
voltage to below the power on reset threshold voltage, the device stops responding to any
instruction sent to it. During Power-down, the device must be deselected (Chip Select (/CS) should
be allowed to follow the voltage applied on VCC) and in Standby Power mode (that is there should
be no internal Write cycle in progress).
5.2 Active Power and Standby Power Modes
When Chip Select (/CS) is Low, the device is selected, and in the Active Power mode. The device
consumes ICC.
When Chip Select (/CS) is High, the device is deselected. If a Write cycle is not currently in
progress, the device then goes in to the Standby Power mode, and the device consumption drops
to ICC1.
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Operation Features
BY25Q64AS
5.3 Hold Condition
The Hold (/HOLD) signal is used to pause any serial communications with the device without
resetting the clocking sequence. During the Hold condition, the Serial Data Output (SO) is high
impedance, and Serial Data Input (SI) and Serial Clock (SCLK) are Don’t Care. To enter the Hold
condition, the device must be selected, with Chip Select (/CS) Low. Normally, the device is kept
selected, for the whole duration of the Hold condition. Deselecting the device while it is in the Hold
condition, has the effect of resetting the state of the device, and this mechanism can be used if it is
required to reset any processes that had been in progress.
The Hold condition starts when the Hold (/HOLD) signal is driven Low at the same time as Serial
Clock (SCLK) already being Low (as shown in Figure 4).The Hold condition ends when the Hold
(HOLD) signal is driven High at the same time as Serial Clock (C) already being Low. Figure 4 also
shows what happens if the rising and falling edges are not timed to coincide with Serial Clock
(SCLK) being Low.
Figure 4. Hold condition activation
/CS
SCLK
/HOLD
HOLD
HOLD
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Operation Features
BY25Q64AS
5.4 Status Register
5.4.1
Status Register Table
See Table 3 for detail description of the Status Register bits.
Table 3. Status Register
S23
Reserved
S22
DRV1
S21
DRV0
S15
SUS1
S14
CMP
S13
LB3
S12
LB2
S11
LB1
S7
SRP0
S6
BP4
S5
BP3
S4
BP2
S3
BP1
5.4.2
S20
Reserved
S19
Reserved
S18
Reserved
S17
Reserved
S16
Reserved
S10
SUS2
S9
QE
S8
SRP1
S2
BP0
S1
WEL
S0
WIP
The Status and Control Bits
5.4.2.1 WIP bit
The Write in Progress (WIP) bit indicates whether the memory is busy in program/erase/write
status register progress. When WIP bit sets to 1, means the device is busy in program/erase/write
status register progress, when WIP bit sets 0, means the device is not in program/erase/write
status register progress.
5.4.2.2 WEL bit
The Write Enable Latch bit indicates the status of the internal Write Enable Latch. When set to 1
the internal Write Enable Latch is set, when set to 0 the internal Write Enable Latch is reset and no
Write Status Register, Program or Erase instruction is accepted.
5.4.2.3 BP4, BP3, BP2, BP1, BP0 bits
The Block Protect (BP4, BP3, BP2, BP1, BP0) bits are non-volatile. They define the size of the
area to be software protected against Program and Erase instructions. These bits are written with
the Write Status Register instruction. When the Block Protect (BP4, BP3, BP2, BP1, BP0) bits are
set to 1, the relevant memory area (as defined in Table 6 and Table 7).becomes protected against
Page Program, Sector Erase and Block Erase instructions. The Block Protect (BP4, BP3, BP2,
BP1, BP0) bits can be written provided that the Hardware Protected mode has not been set. The
Chip Erase(CE) instruction is executed, if the Block Protect(BP2,BP1,BP0)bits are 0 and CMP=0
or The Block Protect (BP2, BP1, BP0) bits are1 and CMP=1.
5.4.2.4 SRP1, SRP0 bits
The Status Register Protect (SRP1 and SRP0) bits are non-volatile Read/Write bits in the status
register. The SRP bits control the method of write protection: software protection, hardware
protection, power supply lock-down or one time programmable protection.
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Operation Features
BY25Q64AS
5.4.2.5 QE bit
The Quad Enable (QE) bit is a non-volatile Read/Write bit in the Status Register that allows Quad
operation. When the QE bit is set to 0 (Default) the /WP pin and /HOLD pin are enable. When the
QE pin is set to 1, the Quad IO2 and IO3 pins are enabled. (The QE bit should never be set to 1
during standard SPI or Dual SPI operation if the /WP or /HOLD pins directly to the power supply or
ground).
5.4.2.6 LB3/LB2/LB1 bit
The LB bit is a non-volatile One Time Program (OTP) bit in Status Register (S13–S11) that provide
the write protect control and status to the Security Registers. The default state of LB is 0, the
security registers are unlocked. LB can be set to 1 individually using the Write Register instruction.
LB is One Time Programmable, once they are set to 1, the Security Registers will become
read-only permanently.
5.4.2.7 CMP bit
The CMP bit is a non-volatile Read/Write bit in the Status Register (S14). It is used in conjunction
the SEC-BP0 bits to provide more flexibility for the array protection. Please see the Status
registers Memory Protection table for details. The default setting is CMP=0.
5.4.2.8 SUS1/SUS2 bit
The SUS1 and SUS2 bits are read only bits in the status register2 (S15 and S10) that are set to 1
after executing an Erase/Program Suspend (75H) instruction (The Erase Suspend will set SUS1 to
1, and the Program Suspend will set the SUS2 to 1). The SUS1 and SUS2 bits are cleared to 0 by
Erase/Program Resume (7AH) instruction as well as a power-down, power-up cycle.
5.4.2.9 DRV1/DRV0
The DRV1&DRV0 bits are used to determine the output driver strength for the Read instruction.
DRV1, DRV0
Apr
Driver Strength
00
100%(default)
01
75%
10
50%
11
25%
2022
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Operation Features
5.4.3
BY25Q64AS
Status Register Protect Table
The Status Register Protect (SRP1 and SRP0) bits are non-volatile Read/Write bits in the Status
Register. The SRP bits control the method of write protection: software protection, hardware
protection, power supply lock-down or one time programmable protection.
Table 4. Status Register protect table
SRP1
SRP0
/WP
Status Register
0
0
X
Software Protected
0
1
0
0
1
1
1
0
X
Power Supply
Lock-Down(1)
1
1
X
One Time
Program(2)
Hardware
Protected
Hardware
Unprotected
Description
The Status Register can be written to after a Write
Enable instruction, WEL=1. (Factory Default)
/WP=0, the Status Register locked and cannot be
written.
/WP=1, the Status Register is unlocked and can be
written to after a Write Enable instruction, WEL=1.
Status Register is protected and cannot be written
to again until the next Power-Down, Power-Up
cycle.
Status Register is permanently protected and
cannot be written to.
Notes:
1. When SRP1, SRP0= (1, 0), a Power-Down, Power-Up cycle will change SRP1, SRP0 to
(0, 0) state.
2. The One time Program feature is available upon special order. Please contact Boya
Microelectronics for details.
5.4.4
1.
Write Protect Features
Software Protection: The Block Protect (BP4, BP3, BP2, BP1, BP0) bits define the section of
the memory array that can be read but not change.
2.
Hardware Protection: /WP going low to protect the writable bits of Status Register.
3.
Deep Power-Down: In Deep Power-Down Mode, all instructions are ignored except the
Release from deep Power-Down Mode instruction.
4.
Write Enable: The Write Enable instruction is set the Write Enable Latch bit. The WEL bit will
return to reset by following situation:
-Power –up
-Write Disable
-Write Status Register
-Page Program
-Sector Erase/Block Erase/Chip Erase
-Software Reset
Apr
2022
Rev 1.9
15 / 76
Operation Features
5.4.5
BY25Q64AS
Status Register Memory Protection
5.4.5.1 Protect Table
Table 5. BY25Q64AS Status Register Memory Protection (CMP=0)
Status Register Content
BP4 BP3 BP2 BP1 BP0
X
X
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
1
1
0
0
1
0
0
0
0
1
0
1
0
0
1
1
0
0
1
0
0
1
0
1
0
1
0
0
1
0
1
1
0
1
1
0
0
0
1
1
0
1
0
1
1
1
0
X
X
1
1
1
1
0
0
0
1
1
0
0
1
0
1
0
0
1
1
1
0
1
0
X
1
0
1
1
0
1
1
0
0
1
1
1
0
1
0
1
1
0
1
1
1
1
1
0
X
1
1
1
1
0
Apr
2022
Blocks
NONE
126 to 127
124 to 127
120 to 127
112 to 127
96 to 127
64 to 127
0 to 1
0 to 3
0 to 7
0 to 15
0 to 31
0 to 63
0 to 127
127
127
127
127
127
0
0
0
0
0
Memory Content
Addresses
Density
NONE
NONE
7E0000H-7FFFFFH
128KB
7C0000H-7FFFFFH 256KB
780000H-7FFFFFH
512KB
700000H-7FFFFFH
1MB
600000H-7FFFFFH
2MB
400000H-7FFFFFH
4MB
000000H-01FFFFH
128KB
000000H-03FFFFH
256KB
000000H-07FFFFH
512KB
000000H-0FFFFFH
1MB
000000H-1FFFFFH
2MB
000000H-3FFFFFH
4MB
000000H-7FFFFFH
8MB
7FF000H-7FFFFFH
4KB
7FE000H-7FFFFFH
8KB
7FC000H-7FFFFFH
16KB
7F8000H-7FFFFFH
32KB
7F8000H-7FFFFFH
32KB
000000H-000FFFH
4KB
000000H-001FFFH
8KB
000000H-003FFFH
16KB
000000H-007FFFH
32KB
000000H-007FFFH
32KB
Rev 1.9
Portion
NONE
Upper 1/64
Upper 1/32
Upper 1/16
Upper 1/8
Upper 1/4
Upper 1/2
Lower 1/64
Lower 1/32
Lower 1/16
Lower 1/8
Lower 1/4
Lower 1/2
ALL
Top Block
Top Block
Top Block
Top Block
Top Block
Bottom Block
Bottom Block
Bottom Block
Bottom Block
Bottom Block
16 / 76
Operation Features
BY25Q64AS
Table 6 BY25Q64AS Status Register Memory Protection (CMP=1)
Status Register Content
Memory Content
BP4
BP3
BP2
BP1
BP0
Blocks
Addresses
Density
Portion
X
X
0
0
0
ALL
000000H-7FFFFFH
ALL
ALL
0
0
0
0
1
0 to 125
000000H-7DFFFFH
8064KB
Lower 63/64
0
0
0
1
0
0 to 123
000000H-7BFFFFH
7936KB
Lower 31/32
0
0
0
1
1
0 to 119
000000H-77FFFFH
7680KB
Lower 15/16
0
0
1
0
0
0 to 111
000000H-6FFFFFH
7MB
Lower 7/8
0
0
1
0
1
0 to 95
000000H-5FFFFFH
6MB
Lower 3/4
0
0
1
1
0
0 to 63
000000H-3FFFFFH
4MB
Lower 1/2
0
1
0
0
1
2 to 127
020000H-7FFFFFH
8064KB
Upper 63/64
0
1
0
1
0
4 to 127
040000H-7FFFFFH
7936KB
Upper 31/32
0
1
0
1
1
8 to 127
080000H-7FFFFFH
7680KB
Upper 15/16
0
1
1
0
0
16 to 127
100000H-7FFFFFH
7MB
Upper 7/8
0
1
1
0
1
32 to 127
200000H-7FFFFFH
6MB
Upper 3/4
0
1
1
1
0
64 to 127
400000H-7FFFFFH
4MB
Upper 1/2
X
X
1
1
1
NONE
NONE
NONE
NONE
1
0
0
0
1
0 to127
000000H-7FEFFFH
8188KB
L-2047/2048
1
0
0
1
0
0 to 127
000000H-7FDFFFH
8184KB
L-1023/1024
1
0
0
1
1
0 to 127
000000H-7FBFFFH
8176KB
L-511/512
1
0
1
0
X
0 to 127
000000H-7F7FFFH
8160KB
L-255/256
1
0
1
1
0
0 to 127
000000H-7F7FFFH
8160KB
L-255/256
1
1
0
0
1
0 to127
001000H-7FFFFFH
8188KB
U-2047/2048
1
1
0
1
0
0 to 127
002000H-7FFFFFH
8184KB
U-1023/1024
1
1
0
1
1
0 to 127
004000H-7FFFFFH
8176KB
U-511/512
1
1
1
0
X
0 to 127
008000H-7FFFFFH
8160KB
U-255/256
1
1
1
1
0
0 to 127
008000H-7FFFFFH
8160KB
U-255/256
Apr
2022
Rev 1.9
17 / 76
Device Identification
6.
BY25Q64AS
Device Identification
Three legacy Instructions are supported to access device identification that can indicate the
manufacturer, device type, and capacity (density). The returned data bytes provide the information
as shown in the below table.
Table 7. BY25Q64AS ID Definition table
Apr
Operation Code
M7-M0
ID15-ID8
ID7-ID0
9FH
90H/92H/94H
ABH
68
68
40
17
16
16
2022
Rev 1.9
18 / 76
Instructions Description
BY25Q64AS
7. Instructions Description
All instructions, addresses and data are shifted in and out of the device, beginning with the most
significant bit on the first rising edge of SCLK after /CS is driven low. Then, the one byte instruction
code must be shifted in to the device, most significant bit first on SI, each bit being latched on the
rising edges of SCLK.
See Table 8, every instruction sequence starts with a one-byte instruction code. Depending on the
instruction, this might be followed by address bytes, or by data bytes, or by both or none. /CS must
be driven high after the last bit of the instruction sequence has been shifted in. For the instruction
of Read, Fast Read, Read Status Register or Release from Deep Power Down, and Read Device
ID, the shifted-in instruction sequence is followed by a data out sequence. /CS can be driven high
after any bit of the data-out sequence is being shifted out.
For the instruction of Page Program, Sector Erase, Block Erase, Chip Erase, Write Status Register,
Write Enable, Write Disable or Deep Power-Down instruction, /CS must be driven high exactly at a
byte boundary, otherwise the instruction is rejected, and is not executed. That is /CS must driven
high when the number of clock pulses after /CS being driven low is an exact multiple of eight. For
Page Program, if at any time the input byte is not a full byte, nothing will happen and WEL will not
be reset.
Apr
2022
Rev 1.9
19 / 76
Instructions Description
BY25Q64AS
Table 8. Instruction Set Table
Instruction Name
Write Enable
Write Disable
Read Status
Register-1
Read Status
Register-2
Read Status
Register-3
Write Enable for
Volatile Status
Register
Write Status
Register -1
Write Status
Register-2
Write Status
Register-3
Read Data
Fast Read
Dual Output Fast
Read
Byte 1
06H
04H
05H
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
(S7-S0)
continuous
35H
(S15-S8)
continuous
15H
(S23-S16)
continuous
50H
01H
(S7-S0)
31H
(S15-S8)
11H
(S23-S16)
03H
0BH
3BH
A23-A16
A23-A16
A23-A16
A15-A8
A15-A8
A15-A8
A7-A0
A7-A0
A7-A0
(D7-D0)
dummy
dummy
Next byte
(D7-D0)
(D7-D0)(1)
Dual I/O Fast Read
BBH
A23-A8(2)
(D7-D0)(1)
Next byte
Next byte
Quad Output Fast
Read
6BH
A23-A16
A7-A0
M7-M0(2)
A15-A8
A7-A0
dummy
(D7-D0)(3)
Quad I/O Fast Read
EBH
dummy(5)
(D7-D0)(3)
Next byte
Next byte
dummy(6)
(D7-D0)(3)
Next byte
Next byte
A15-A8
A15-A8
A15-A8
A15-A8
A15-A8
A15-A8
A7-A0
A7-A0
A7-A0
A7-A0
A7-A0
A7-A0
(D7-D0)
(D7-D0)(3)
(D7-D0)
Next byte
Next byte
Next byte
dummy
dummy
dummy
(ID7-ID0)
90H
dummy
dummy
00H
(MID7-MID0)
92H
A23-A8
A7-A0,
dummy
(MID7-MID
0),(DID7-D
ID0)
Quad I/O Word
Fast Read(7)
Page Program
Quad Page Program
Fast Page Program
Sector Erase
Block Erase(32K)
Block Erase(64K)
Chip Erase
Enable Reset
Reset
Set Burst with Wrap
Program/Erase
Suspend
Program/Erase
Resume
Deep Power-Down
Release From Deep
Power-Down, And
Read Device ID
Release From Deep
Power-Down
Manufacturer/
Device ID
Manufacturer/
Device ID by Dual
I/O
Apr
2022
N-Bytes
E7H
02H
32H
F2H
20H
52H
D8H
C7/60H
66H
99H
77H
A23-A0
M7-M0(4)
A23-A0
dM7-M0 (4)
A23-A16
A23-A16
A23-A16
A23-A16
A23-A16
A23-A16
continuous
continuous
continuous
continuous
continuous
continuous
continuous
continuous
continuous
continuous
dummy(6)
W7-W0
75H
7AH
B9H
continuous
ABH
ABH
Rev 1.9
(ID7-ID0)
continuous
continuous
20 / 76
Instructions Description
A23-A0,
dummy
BY25Q64AS
dummy(10)
Manufacturer/
Device ID by Quad
I/O
94H
continuous
JEDEC ID
Read Serial Flash
Discoverable
Parameter
Erase Security
Registers(8)
Program Security
Registers(8)
Read Security
Registers(8)
9FH
MID7-MID0
ID15-ID8
ID7-ID0
5AH
A23-A16
A15-A8
A7-A0
44H
A23-A16
A15-A8
A7-A0
42H
A23-A16
A15-A8
48H
A23-A16
A15-A8
(MID7-MID0)
(DID7-DID0)
continuous
Dummy
D7-D0
A7-A0
(D7-D0)
(D7-D0)
A7-A0
dummy
(D7-D0)
continuous
continuous
continuous
Notes:
1. Dual Output data
IO0 = (D6, D4, D2, D0)
IO1 = (D7, D5, D3, D1)
2. Dual Input Address
IO0 = A22, A20, A18, A16, A14, A12, A10, A8, A6, A4, A2, A0, M6, M4, M2, M0
IO1 = A23, A21, A19, A17, A15, A13, A11, A9, A7, A5, A3, A1, M7, M5, M3,M1
3. Quad Output Data
IO0 = (D4, D0,…..)
IO1 = (D5, D1,…..)
IO2 = (D6, D2,…..)
IO3 = (D7, D3,…..)
4. Quad Input Address
IO0 = A20, A16, A12, A8, A4, A0, M4, M0
IO1 = A21, A17, A13, A9, A5, A1, M5, M1
IO2 = A22, A18, A14, A10, A6, A2, M6, M2
IO3 = A23, A19, A15, A11, A7, A3, M7, M3
5. Fast Read Quad I/O Data
IO0 = (x, x, x, x, D4, D0,…)
IO1 = (x, x, x, x, D5, D1,…)
IO2 = (x, x, x, x, D6, D2,…)
IO3 = (x, x, x, x, D7, D3,…)
6. Fast Word Read Quad I/O Data
IO0 = (x, x, D4, D0,…)
IO1 = (x, x , D5, D1,…)
IO2 = (x, x, D6, D2,…)
IO3 = (x, x, D7, D3,…)
7. Fast Word Read Quad I/O Data: the lowest address bit must be 0.
8. Security Registers Address:
Security Register1: A23-A16=00H, A15-A8=00010000b, A7-A0= Byte Address;
Security Register2: A23-A16=00H, A15-A8=00100000b, A7-A0= Byte Address;
Security Register3: A23-A16=00H, A15-A8=00110000b, A7-A0= Byte Address;
9. Dummy bits and Wraps Bits
IO0 = (x, x, x, x, x, x, w4, x)
IO1 = (x, x, x, x, x, x, w5, x)
IO2 = (x, x, x, x, x, x, w6, x)
IO3 = (x, x, x, x, x, x, x,x)
10. Address, continuous Read Mode bits, Dummy bits, Manufacture ID and Device ID
IO0 = (A20, A16, A12, A8, A4, A0, M4, M0, x, x, x, x, MID4, MID0, DID4, DID0)
IO1 = (A21, A17, A13, A9, A5, A1, M5, M1, x, x, x, x, MID5, MID1, DID5, DID1)
IO2 = (A22, A18, A14, A10, A6, A2, M6, M2, x, x, x, x, MID6, MID2, DID6, DID2)
IO3 = (A23, A19, A15, A11, A7, A3, M7, M3, x, x, x, x, MID7, MID3, DID7, DID3)
11. Security Register 0 can be used to store the Flash Discoverable Parameters,
The feature is upon special order, please contact Boya Microelectronics for details.
Apr
2022
Rev 1.9
21 / 76
Instructions Description
BY25Q64AS
7.1 Configuration and Status Instructions
7.1.1
Write Enable (06H)
See Figure 5, the Write Enable instruction is for setting the Write Enable Latch bit. The Write
Enable Latch bit must be set prior to every Page Program, Sector Erase, Block Erase, Chip Erase,
Write Status Register instruction and Erase/Program Security Registers instruction. The Write
Enable instruction sequence: /CS goes low sending the Write Enable instruction /CS goes high.
Figure 5. Write Enable Sequence Diagram
/CS
0
1
2
3
4
5
6
7
SCLK
Instruction
SI
06H
High_Z
SO
7.1.2
Write Disable (04H)
See Figure 6, the Write Disable instruction is for resetting the Write Enable Latch bit. The Write
Disable instruction sequence: /CS goes low -> sending the Write Disable instruction -> /CS goes
high. The WEL bit is reset by following condition: Power-up and upon completion of the Write Status
Register, Page Program, Sector Erase, Block Erase and Chip Erase, Erase/Program Security
Registers and Reset instructions.
Figure 6. Write Disable Sequence Diagram
/CS
0
1
2
3
4
5
6
7
SCLK
Instruction
SI
SO
Apr
2022
04H
High_Z
Rev 1.9
22 / 76
Instructions Description
7.1.3
BY25Q64AS
Read Status Register (05H or 35H or 15H)
See Figure 7 the Read Status Register (RDSR) instruction is for reading the Status Register. The
Status Register may be read at any time, even while a Program, Erase or Write Status Register
cycle is in progress. When one of these cycles is in progress, it is recommended to check the Write
in Progress (WIP) bit before sending a new instruction to the device. It is also possible to read the
Status Register continuously. For instruction code “05H”, the SO will output Status Register bits
S7~S0. The instruction code “35H”, the SO will output Status Register bits S15~S8, The instruction
code “15H”, the SO will output Status Register bits S23~16.
Figure 7. Read Status Register Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
SCLK
Instruction
SI
05H or 35H or 15H
Register 0/1/2
High_Z
SO
7.1.4
7 6
MSB
5
4
Register 0/1/2
2
3
1
0
7 6
MSB
5
4
3
2
1
0
Write Status Register (01H or 31H or 11H)
See Figure 8, the Write Status Register instruction allows new values to be written to the Status
Register. Before it can be accepted, a Write Enable instruction must previously have been
executed. After the Write Enable instruction has been decoded and executed, the device sets the
Write Enable Latch (WEL).
The Write Status Register instruction has no effect on S23, S20, S19, S18, S17, S16, S15, S1 and
S0 of the Status Register. /CS must be driven high after the eighth bit of the data byte has been
latched in. If not, the Write Status Register instruction is not executed. As soon as /CS is driven high,
the self-timed Write Status Register cycle (whose duration is tW) is initiated. While the Write Status
Register cycle is in progress, the Status Register may still be read to check the value of the Write in
Progress (WIP) bit. The Write in Progress (WIP) bit is 1 during the self-timed Write Status Register
cycle, and is 0 when it is completed. When the cycle is completed, the Write Enable Latch is reset.
The Write Status Register instruction allows the user to change the values of the Block Protect
(BP4, BP3, BP2, BP1, BP0) bits, to define the size of the area that is to be treated as read-only, as
defined in Table 3. The Write Status Register instruction also allows the user to set or reset the
Status Register Protect (SRP1 and SRP0) bits in accordance with the Write Protect (/WP) signal.
The Status Register Protect (SRP1 and SRP0) bits and Write Protect (/WP) signal allow the device
to be put in the Hardware Protected Mode. The Write Status Register instruction is not executed
once the Hardware Protected Mode is entered.
Figure 8. Write Status Register Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
SCLK
Status Register in
Instruction
SI
01H or 31H or 11H
7
6
5
4
3
2
1
0
MSB
High_Z
SO
Apr
2022
Rev 1.9
23 / 76
Instructions Description
7.1.5
BY25Q64AS
Write Enable for Volatile Status Register (50H)
See Figure 9, the non-volatile Status Register bits can also be written to as volatile bits. This gives
more flexibility to change the system configuration and memory protection schemes quickly
without waiting for the typical non-volatile bit write cycles or affecting the endurance of the Status
Register non-volatile bits. Write Enable for Volatile Status Register instruction will not set the Write
Enable Latch bit, it is only valid for the Write Status Registers instruction to change the volatile
Status Register bit values.
Figure 9. Write Enable for Volatile Status Register
/CS
0
1
2
3
4
5
6
7
SCLK
Instruction
SI
SO
Apr
2022
50H
High_Z
Rev 1.9
24 / 76
Instructions Description
BY25Q64AS
7.2 Read Instructions
7.2.1
Read Data (03H)
See Figure 10, the Read Data Bytes (READ) instruction is followed by a 3-byte address (A23-A0),
each bit being latched-in during the rising edge of SCLK. Then the memory content, at that
address, is shifted out on SO, each bit being shifted out, at a Max frequency fR, during the falling
edge of SCLK. The address is automatically incremented to the next higher address after each
byte of data is shifted out allowing for a continuous stream of data. This means that the entire
memory can be accessed with a single command as long as the clock continues. The command is
completed by driving /CS high. The whole memory can be read with a single Read Data Bytes
(READ) instruction. Any Read Data Bytes (READ) instruction, while an Erase, Program or Write
cycle is in progress, is rejected without having any effects on the cycle that is in progress.
Figure 10. Read Data Bytes Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
10
28 29 30 31 32 33 34 35 36 37 38 39
SCLK
24-Bit Address
Instruction
SI
03H
23 22
21
3
2
1
0
Data Byte1
MSB
High_Z
SO
Apr
2022
7 6
MSB
Rev 1.9
5
4
3
High_Z
2
25 / 76
1
0
Instructions Description
7.2.2
BY25Q64AS
Fast Read (0BH)
See Figure 11, the Read Data Bytes at Higher Speed (Fast Read) instruction is for quickly reading
data out. It is followed by a 3-byte address (A23-A0) and a dummy byte, each bit being latched-in
during the rising edge of SCLK. Then the memory content, at that address, is shifted out on SO,
each bit being shifted out, at a Max frequency fc, during the falling edge of SCLK. The first byte
addressed can be at any location. The address is automatically incremented to the next higher
address after each byte of data is shifted out.
Figure 11. Fast Read Sequence Diagram
/CS
0
1
2
3
4
5
6
7
9
8
28 29 30
10
31
SCLK
Instruction
24-Bit Address
23 22
0BH
SI
21
3
2
1
0
High_Z
SO
/CS
32 33 34 35 36
37 38 39 40 41 42 43 44
45 46 47
SCLK
Dummy Clocks
High_Z
SI
High_Z
SO
Apr
2022
Data byte 1
7
Rev 1.9
6
5
4
3
High_Z
2
1
0
26 / 76
Instructions Description
7.2.3
BY25Q64AS
Dual Output Fast Read (3BH)
See Figure 12, the Dual Output Fast Read instruction is followed by 3-byte address (A23-A0) and a
dummy byte, each bit being latched in during the rising edge of SCLK, then the memory contents
are shifted out 2-bit per clock cycle from SI and SO. The first byte addressed can be at any location.
The address is automatically incremented to the next higher address after each byte of data is
shifted out.
Figure 12. Dual Output Fast Read Sequence Diagram
/CS
0
1
2
3
4
5
6
7
9
8
28
10
29
30
31
SCLK
Instruction
24-Bit Address
3BH
SI
SO
23
22
21
41
42
43
3
2
1
0
High_Z
/CS
32
33
34
35
36
37
38
39
40
44
45
46
47
6
4
2
0
SCLK
Dummy Clocks
SI
6
4
2
0
Data Byte 2
Data Byte 1
High_Z
SO
Apr
2022
7
5
Rev 1.9
3
1
7
5
3
1
27 / 76
High_Z
High_Z
Instructions Description
7.2.4
BY25Q64AS
Quad Output Fast Read (6BH)
See Figure 13, the Quad Output Fast Read instruction is followed by 3-byte address (A23-A0) and
a dummy byte, each bit being latched in during the rising edge of SCLK, then the memory contents
are shifted out 4-bit per clock cycle from IO3, IO2, IO1 and IO0. The first byte addressed can be at
any location. The address is automatically incremented to the next higher address after each byte
of data is shifted out.
Figure 13. Quad Output Fast Read Sequence Diagram
/CS
0
1
3
2
4
5
6
8
7
9
28
10
29
30
31
SCLK
24-Bit Address
Instruction
SI
(IO0)
6BH
SO
(IO1)
High_Z
/WP
(IO2)
High_Z
/HOLD
(IO3)
High_Z
/CS
32
33
34
35
36
37
38
39
40
3
2
1
45
46
47
21
22
23
41
42
4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
7
3
Byte1
7
3
7
3
Byte3
43
44
0
SCLK
SI
(IO0)
Dummy Clocks
SO
(IO1)
High_Z
/WP
(IO2)
High_Z
/HOLD
(IO3)
High_Z
Apr
2022
Rev 1.9
Byte2
3
7
Byte4
28 / 76
High_Z
High_Z
High_Z
High_Z
Instructions Description
7.2.5
BY25Q64AS
Dual I/O Fast Read (BBH)
See Figure 14, the Dual I/O Fast Read instruction is similar to the Dual Output Fast Read
instruction but with the capability to input the 3-byte address (A23-0) and a “Continuous Read Mode”
byte 2-bit per clock by SI and SO, each bit being latched in during the rising edge of SCLK, then the
memory contents are shifted out 2-bit per clock cycle from SI and SO. The first byte addressed can
be at any location. The address is automatically incremented to the next higher address after each
byte of data is shifted out.
Dual I/O Fast Read with “continuous Read Mode”
The Dual I/O Fast Read instruction can further reduce instruction overhead through setting the
“continuous Read Mode ”bits (M7-4) after the inputs 3-byte address A23-A0).If the “continuous
Read Mode ”bits(M5-4)=(1,0),then the next Dual I/O fast Read instruction (after CS/ is raised and
then lowered) does not require the BBH instruction code. The instruction sequence is shown in the
following Figure15.If the “continuous Read Mode” bits (M5-4) does not equal (1,0), the next
instruction requires the first BBH instruction code, thus returning to normal operation. A “continuous
Read Mode” Reset instruction can be used to reset (M5-4) before issuing normal instruction.
Figure 14. Dual I/O Fast Read Sequence Diagram (Initial command or previous (M5-4)≠(1,0)))
/CS
0
1
2
3
4
5
6
7
9
8
10 11 12
13 14 15 16 17 18 19 20 21 22 23
SCLK
Instruction
SI
(IO0)
BBH
SO
(IO1)
High_Z
6
4
2
0
6
4
2
0
6
4
2
0
6
4
2
0
7
5
3
1
7
5
3
1
7
5
3
1
7
5
3
1
A23-16
A15-8
A7-0
M7-0
/CS
SCLK
23 24 25 26
27 28 29 30
31 32 33
34 35 36 37 38 39
SI
(IO0)
6
4
2
0
6
4
2
0
6
4
2
0
6
4
2
0
SO
(IO1)
7
5
3
1
7
5
3
1
7
5
3
1
7
3
5
Byte 4
1
Byte 1
Apr
2022
Byte 2
Byte 3
Rev 1.9
High_Z
High_Z
29 / 76
Instructions Description
BY25Q64AS
Figure 15. Dual I/O Fast Read Sequence Diagram (Previous command set (M5-4) =(1,0))
/CS
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
SCLK
SI
(IO0)
6
SO
(IO1)
7
/CS
Apr
0
6
4
0
6
4
2
0
6
4
2
0
5 3 1
A23-16
7
5 3 1
A15-8
7
5 3
A7-0
1
7
5 3
M7-0
1
4
2
2
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
SCLK
SI
(IO0)
6
4
2
0
6
4
0
6
4
2
0
6
SO
(IO1)
7
5 3
Byte1
1
7
5 3 1
Byte2
7
5 3
Byte3
1
7
2022
2
Rev 1.9
2
0
5 3
Byte4
1
4
30 / 76
Instructions Description
7.2.6
BY25Q64AS
Quad I/O Fast Read (EBH)
See Figure 16, the Quad I/O Fast Read instruction is similar to the Dual I/O Fast Read instruction
but with the capability to input the 3-byte address (A23-0) and a “Continuous Read Mode” byte
and 4-dummy clock 4-bit per clock by IO0, IO1, IO3, IO4, each bit being latched in during the rising
edge of SCLK, then the memory contents are shifted out 4-bit per clock cycle from IO0, IO1, IO2,
IO3. The first byte addressed can be at any location. The address is automatically incremented to
the next higher address after each byte of data is shifted out. The Quad Enable bit (QE) of Status
Register must be set to enable for the Quad I/O Fast read instruction.
Quad I/O Fast Read with “Continuous Read Mode”
The Quad I/O Fast Read instruction can further reduce instruction overhead through setting the
“Continuous Read Mode” bits (M7-0) after the input Address bits (A23-0), as shown in Figure 16, If
the “Continuous Read Mode” bits (M5-4 )= (1,0), then the next Fast Read Quad I/O
instruction(after /CS is raised and then lowered) does not require the EBH instruction code, The
instruction sequence is shown in the followed Figure 17. If the “Continuous Read Mode” bits M5-4
do not equal to (1,0), the next instruction requires the first EBH instruction code, thus returning to
normal operation. A “Continuous Read Mode” Reset command can also be used to reset (M5-4)
before issuing normal command.
Figure 16. Quad I/O Fast Read Sequence Diagram (Initial command or previous (M5-4≠(1,0)))
/CS
0
1
2
3
4
5
6
7
9
8
10 11 12 13 14 15 16 17 18 19 20 21 22 23
SCLK
Instruction
SI
(IO0)
EBH
SO
(IO1)
High_Z
/WP
(IO2)
High_Z
/HOLD
(IO3)
High_Z
Apr
2022
4
0
4
0
4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
6
2
6
2
7 3
A7-0
7
3
7 3 7 3
A23-16 A15-8
Rev 1.9
Dummy
7 3
Byte1
31 / 76
7 3
Byte2
Instructions Description
BY25Q64AS
Figure 17. Quad I/O Fast Read Sequence Diagram (Previous command set (M5-4)=(1,0)))
/CS
0
SCLK
SI
(IO0)
SO
(IO1)
/WP
(IO2)
/HOLD
(IO3)
1
2
3
4
6
5
7
8
9
10 11 12 13 14 15
4
0
4
0
4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
6
2
6
2
7
3
7
3
7
3
7
3
7 3
Byte1
A23-16
A15-8
A7-0
M7-0
Dummy
7 3
Byte2
Quad I/O Fast Read with “8/16/32/64-Byte Wrap Around”
The Quad I/O Fast Read instruction can also be used to access a specific portion within a page by
issuing a “Set Burst with Wrap” (77H) instruction prior to EBH. The “Set Burst with Wrap” (77H)
instruction can either enable or disable the “Wrap Around” feature for the following EBH
instructions. When “Wrap Around” is enabled, the data being accessed can be limited to either an
8, 16, 32 or 64-byte section of a 256-byte page. The output data starts at the initial address
specified in the instruction, once it reaches the ending boundary of the 8/16/32/64-byte section,
the output will wrap around to the beginning boundary automatically until /CS is pulled high to
terminate the instruction.
The Burst with Wrap feature allows applications that use cache to quickly fetch a critical address
and then fill the cache afterwards within a fixed length (8/16/32/64-byte) of data without issuing
multiple read instructions.
The “Set Burst with Wrap” instruction allows three “Wrap Bits”, W6-4 to be set. The W4 bit is used
to enable or disable the “Wrap Around” operation while W6-5 are used to specify the length of the
wrap around section within a page.
Apr
2022
Rev 1.9
32 / 76
Instructions Description
7.2.7
BY25Q64AS
Quad I/O Word Fast Read (E7H)
The Quad I/O Word Fast Read instruction is similar to the Quad Fast Read instruction except that
the lowest address bit (A0) must equal 0 and 2-dummy clock. The instruction sequence is shown
in the followed Figure 18, the first byte addressed can be at any location. The address is
automatically incremented to the next higher address after each byte of data is shifted out. The
Quad Enable bit (QE) of Status Register (S9) must be set to enable for the Quad I/O Word Fast
Read instruction.
Quad I/O Word Fast Read with “Continuous Read Mode”
The Quad I/O Word Fast Read instruction can further reduce instruction overhead through setting
the “Continuous Read Mode” bits (M7-0) after the input 3-byte Address bits (A23-0). If the
“Continuous Read Mode” bits (M5-4) = (1, 0), then the next Quad I/O Fast Read instruction (after
/CS is raised and then lowered) does not require the E7H instruction code, the instruction
sequence is shown in the followed Figure 19. If the “Continuous Read Mode” bits M5-4 do not
equal to (1,0), the next instruction requires the first E7H instruction code, thus returning to normal
operation. A “Continuous Read Mode” Reset command can also be used to reset (M5-4) before
issuing normal command.
Figure 18. Quad I/O Word Fast Read Sequence Diagram (Initial command or previous (M5-4)≠
(1,0))
/CS
0
1
2
3
4
6
5
7
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
8
SCLK
SI
(IO0)
Instruction
E7H
SO
(IO1)
High_Z
/WP
(IO2)
High_Z
/HOLD
(IO3)
High_Z
4
0
4
0
4
0
4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
6
2
6
2
6
2
7 3 7 3
A23-16 A15-8
7 3
A7-0
7 3
M7-M0 Dummy
7
3
Byte1
7 3
Byte2
7 3
Byte3
Figure 19. Quad I/O word Fast Read Sequence Diagram (Previous command set (M5-4) =(1,0))
/CS
0
SCLK
SI
(IO0)
SO
(IO1)
/WP
(IO2)
/HOLD
(IO3)
1
2022
3
4
6
5
7
8
9 10 11 12 13 14 15
4
0
4
0
4
0 4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
6
2
6
2
6
2
7
3
7
3
7
3
7
A23-16
Apr
2
A15-8
A7-0
7 3
Dummy Byte1
M7-0
3
Rev 1.9
7 3
Byte2
7 3
Byte3
33 / 76
Instructions Description
BY25Q64AS
Quad I/O Word Fast Read with “8/16/32/64-Byte Wrap Around” in standard SPI mode
The Quad I/O Fast Read instruction can also be used to access a specific portion within a page by
issuing a “Set Burst with Wrap” (77H) instruction prior to E7H. The “Set Burst with Wrap” (77H)
instruction can either enable or disable the “Wrap Around” feature for the following E7H
instructions. When “Wrap Around” is enabled, the data being accessed can be limited to either an
8, 16, 32 or 64-byte section of a 256-byte page. The output data starts at the initial address
specified in the instruction, once it reaches the ending boundary of the 8/16/32/64-byte section,
the output will wrap around to the beginning boundary automatically until /CS is pulled high to
terminate the instruction.
The Burst with Wrap feature allows applications that use cache to quickly fetch a critical address
and then fill the cache afterwards within a fixed length (8/16/32/64-byte) of data without issuing
multiple read instructions.
The “Set Burst with Wrap” instruction allows three “Wrap Bits”, W6-4 to be set. The W4 bit is used
to enable or disable the “Wrap Around” operation while W6-5 are used to specify the length of the
wrap around section within a page.
Apr
2022
Rev 1.9
34 / 76
Instructions Description
7.2.8
BY25Q64AS
Set Burst with Wrap (77H)
See Figure 20, The Set Burst with Wrap instruction is used in conjunction with ”Quad I/O Fast
Read” and “Quad I/O Word Fast Read” instruction to access a fixed length of 8/16/32/64-byte
section within a 256-byte page, in standard SPI mode.
The Set Burst with Wrap instruction sequence:/CS goes low ->Send Set Burst with Wrap
instruction ->Send24 Dummy bits ->Send 8 bits “Wrap bits”->/CS goes high.
If W6-4 is set by a Set Burst with Wrap instruction, all the following “Fast Read Quad I/O” and
“Word Read Quad I/O” instructions will use the W6-4 setting to access the 8/16/32/64-byte section
within any page. To exit the “Wrap Around” function and return to normal read operation, another
Set Burst with Wrap instruction should be issued to set W4=1. The default value of W4 upon
power on is 1.
W4 = 0
W4 =1 (DEFAULT)
W6 , W5
Wrap Around
Wrap Length
Wrap Around
Wrap Length
0
0
Yes
8-byte
No
N/A
0
1
1
1
0
1
Yes
Yes
Yes
16-byte
32-byte
64-byte
No
No
No
N/A
N/A
N/A
Figure 20. Set Burst with Wrap Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
11
10
12
13
14
15
SCLK
Instruction
SI
(IO0)
SO
(IO1)
x
x
x
x
x
x
W4
x
High_Z
x
x
x
x
x
x
x
High_Z
W5
x
x
x
x
x
x
x
High_Z
W6
x
x
x
x
x
x
x
x
High_Z
/WP
(IO2)
High_Z
/HOLD
(IO3)
High_Z
Byte1
Apr
2022
High_Z
77H
Rev 1.9
Byte2
Byte3
Byte4
35 / 76
Instructions Description
BY25Q64AS
7.3 ID and Security Instructions
7.3.1
Read Manufacture ID/ Device ID (90H)
See Figure 21, The Read Manufacturer/Device ID instruction is an alternative to the Release from
Power-Down/Device ID instruction that provides both the JEDEC assigned Manufacturer ID and
the specific Device ID.
The instruction is initiated by driving the /CS pin low and shifting the instruction code “90H”
followed by a 24-bit address (A23-A0) of 000000H. If the 24-bit address is initially set to 000001H,
the Device ID will be read first.
Figure 21. Read Manufacture ID/ Device ID Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
10
28 29 30 31
SCLK
Instruction
SI
24-Bit Address
3 2
23 22 21
90H
High_Z
SO
1
/CS
32 33 34 35 36
37 38 39 40 41 42
43 44 45 46 47
SCLK
SI
SO
Apr
7
2022
6
Manufacturer ID
5 4
3 2
1
0
7
Rev 1.9
6
Device ID
3 2
5 4
1
0
36 / 76
0
Instructions Description
7.3.2
BY25Q64AS
Dual I/O Read Manufacture ID/ Device ID (92H)
See Figure 22, the Dual I/O Read Manufacturer/Device ID instruction is an alternative to the
Release from Power-Down/Device ID instruction that provides both the JEDEC assigned
Manufacturer ID and the specific Device ID by Dual I/O.
The instruction is initiated by driving the /CS pin low and shifting the instruction code “92H”
followed by a 24-bit address (A23-A0) of 000000H. If the 24-bit address is initially set to 000001H,
the Device ID will be read first.
Figure 22. Dual I/O Read Manufacture ID/ Device ID Sequence Diagram
/CS
0
1
2
4
3
5
6
7
9
8
10 11 12
13 14 15 16 17 18 19 20 21 22 23
SCLK
Instruction
SI
(IO0)
92H
SO
(IO1)
High_Z
6
4
2
0
6
4
2
0
6
4
2
0
6
4
2
0
7
5
3
1
7
5
3
1
7
5
3
1
7
5
3
1
A23-16
A15-8
A7-0
Dummy
/CS
SCLK
23 24 25 26
27 28 29 30
39
31 32
SI
(IO0)
6
4
2
0
6
4
2
0
SO
(IO1)
7
5
3
1
7
5
3
1
40 41 42 43
6
44 45 46 47
0
6
7
5 3 1
MFR ID(repeat)
7
4
2
4
2
0
High_Z
High_Z
MFR ID
Apr
2022
Device ID
MFR and Device ID
(repeat)
Rev 1.9
3 1
5
Device ID(repeat)
37 / 76
Instructions Description
7.3.3
BY25Q64AS
Quad I/O Read Manufacture ID/ Device ID (94H)
See Figure 23, the Quad I/O Read Manufacturer/Device ID instruction is an alternative to the
Release from Power-Down/Device ID instruction that provides both the JEDEC assigned
Manufacturer ID and the specific Device ID by quad I/O.
The instruction is initiated by driving the /CS pin low and shifting the instruction code “94H”
followed by a 24-bit address (A23-A0) of 000000H and4 dummy clocks. If the 24-bit address is
initially set to 000001H, the Device ID will be read first.
Figure 23. Quad I/O Read Manufacture ID/ Device ID Sequence Diagram
/CS
0
1
2
3
4
5
6
7
9
8
10 11 12
13 14 15 16 17 18 19 20 21
22 23
SCLK
Instruction
SI
(IO0)
94H
SO
(IO1)
High_Z
WP
(IO2)
High_Z
HOLD
(IO3)
High_Z
4
0
4
0
4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
6
2
6
2
7
3
7
3
7
3
7
3
7
3
7
3
A23-16
A15-8
A7-0
dummy
dummy
MFR ID Device ID
/CS
SCLK
23 24 25 26
27 28 29 30
31
SI
(IO0)
4
0
4
0
4
0
4
0
SO
(IO1)
5
1
5
1
5
1
5
1
WP
(IO2)
6
2
6
2
6
2
6
2
7
3
7
3
7
3
7
3
HOLD
(IO3)
MFR ID DID ID MFR ID DID ID
(repeat) (repeat) (repeat) (repeat)
Apr
2022
Rev 1.9
38 / 76
Instructions Description
7.3.4
BY25Q64AS
Read JEDEC ID (9FH)
The JEDEC ID instruction allows the 8-bit manufacturer identification to be read, followed by two
bytes of device identification. The device identification indicates the memory type in the first byte,
and the memory capacity of the device in the second byte. JEDEC ID instruction while an Erase or
Program cycle is in progress, is not decoded, and has no effect on the cycle that is in progress.
The JEDEC ID instruction should not be issued while the device is in Deep Power-Down Mode.
See Figure 24, The device is first selected by driving /CS to low. Then, the 8-bit instruction code for
the instruction is shifted in. This is followed by the 24-bit device identification, stored in the memory,
being shifted out on Serial Data Output, each bit being shifted out during the falling edge of Serial
Clock. The JEDEC ID instruction is terminated by driving /CS to high at any time during data
output. When /CS is driven high, the device is put in the Standby Mode. Once in the Standby
Mode, the device waits to be selected, so that it can receive, decode and execute instructions.
Figure 24. JEDEC ID Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
10
11 12 13
14 15
SCLK
9FH
Instruction
SI
Manufacturer ID
7
MSB
SO
/CS
16 17 18 19
20 21 22 23 24
6
25 26
5
4
3
27 28 29
2
1
30 31
SCLK
SI
SO
7
MSB
Apr
2022
Memory Type ID15-ID8
1
6 5 4 3 2
0
7
Capacity ID7-ID0
6 5 4 3 2 1
0
MSB
Rev 1.9
39 / 76
0
Instructions Description
7.3.5
BY25Q64AS
Read Unique ID Number (4Bh)
The Read Unique ID Number instruction accesses a factory-set read-only 64-bit number that is
unique to each BY25Q64 device. The ID number can be used in conjunction with user software
methods to help prevent copying or cloning of a system. The Read Unique ID instruction is
initiated by driving the /CS pin low and shifting the instruction code “4Bh” followed by a four bytes
of dummy clocks. After which, the 64-bit ID is shifted out on the falling edge of SCLK as shown in
Figure 25.
Figure 25. Read Unique ID Sequence Diagram
/CS
SCLK
0
Mode 3
Mode 0
1
2
3
4
5
6
7
8
9
10
Instruction
SI
11
12
13
14
15
16
Dummy Byte 1
17
18
19
20
21
22
23
Dummy Byte 2
4BH
SO
High_Z
/CS
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
100 101 102 103
SCLK
Dummy Byte 3
Dummy Byte 4
SI
High_Z
SO
Apr
2022
63
MSB
Rev 1.9
62
2
1
64-bit Unique
Serial Number
40 / 76
0
Mode 3
Mode 0
Instructions Description
7.3.6
BY25Q64AS
Deep Power-Down (B9H)
Although the standby current during normal operation is relatively low, standby current can be
further reduced with the Deep Power-down instruction. The lower power consumption makes the
Deep Power-down (DPD) instruction especially useful for battery powered applications (see ICC1
and ICC2). The instruction is initiated by driving the /CS pin low and shifting the instruction code
“B9h” as shown in Figure 26.
The /CS pin must be driven high after the eighth bit has been latched. If this is not done the Deep
Power down instruction will not be executed. After /CS is driven high, the power-down state will
entered within the time duration of tDP. While in the power-down state only the Release from Deep
Power-down / Device ID instruction, which restores the device to normal operation, will be
recognized. All other Instructions are ignored. This includes the Read Status Register instruction,
which is always available during normal operation. Ignoring all but one instruction also makes the
Power Down state a useful condition for securing maximum write protection. The device always
powers-up in the normal operation with the standby current of ICC1.
Figure 26. Deep Power-Down Sequence Diagram
/CS
0
1
2
3 4
5
6
7
tDP
SCLK
Instruction
SI
B9H
Stand-by mode
Apr
2022
Rev 1.9
Power-down mode
41 / 76
Instructions Description
7.3.7
BY25Q64AS
Release from Deep Power-Down/Read Device ID (ABH)
The Release from Power-Down or Device ID instruction is a multi-purpose instruction. It can be
used to release the device from the Power-Down state or obtain the devices electronic
identification (ID) number.
See Figure 27, to release the device from the Power-Down state, the instruction is issued by
driving the /CS pin low, shifting the instruction code “ABH” and driving /CS high Release from
Power-Down will take the time duration of tRES1 (See AC Characteristics) before the device will
resume normal operation and other instruction are accepted. The /CS pin must remain high during
the tRES1 time duration.
When used only to obtain the Device ID while not in the Power-Down state, the instruction is
initiated by driving the /CS pin low and shifting the instruction code “ABH” followed by 3-dummy
byte. The Device ID bits are then shifted out on the falling edge of SCLK with most significant bit
(MSB) first as shown in Figure 28. The Device ID value for the BY25Q64AS is listed in
Manufacturer and Device Identification table. The Device ID can be read continuously. The
instruction is completed by driving /CS high.
When used to release the device from the Power-Down state and obtain the Device ID, the
instruction is the same as previously described, and shown in Figure 28, except that after /CS is
driven high it must remain high for a time duration of tRES2 (See AC Characteristics). After this
time duration the device will resume normal operation and other instruction will be accepted. If the
Release from Power-Down/Device ID instruction is issued while an Erase, Program or Write cycle
is in process (when WIP equal 1) the instruction is ignored and will not have any effects on the
current cycle.
Figure 27. Release Power-Down Sequence Diagram
/CS
1
0
2
3 4
5
6
tRES1
7
SCLK
Instruction
SI
ABH
Power-down mode
Stand-by mode
Figure 28. Release Power-Down/Read Device ID Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
29
30
31 32
33
34
35
36
37
38
39
SCLK
Instruction
SI
ABH
SO
High_Z
3 Dummy Bytes
23 22
2
1
MSB
tRES2
0
7
MSB
6
Device ID
3
4
5
2
1
0
Deep Power-down mode
Apr
2022
Rev 1.9
42 / 76
Stand-by mode
Instructions Description
7.3.8
BY25Q64AS
Read Security Registers (48H)
See Figure 29, the Read Security Registers instruction is similar to Fast Read instruction. The
instruction is followed by a 3-byte address (A23-A0) and a dummy byte, each bit being latched-in
during the rising edge of SCLK. Then the memory content, at that address, is shifted out on SO,
each bit being shifted out, at a Max frequency fC, during the falling edge of SCLK. The first byte
addressed can be at any location. The address is automatically incremented to the next higher
address after each byte of data is shifted out. Once the A7-A0 address reaches the last byte of the
register (Byte FFH), it will reset to 000H, the instruction is completed by driving /CS high.
Address
A23-A16
A15-A12
A11-A8
A7-A0
Security Registers 1
00H
0001
0000
Byte Address
Security Registers 2
00H
0010
0000
Byte Address
Security Registers 3
00H
0011
0000
Byte Address
Figure 29. Read Security Registers instruction Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
28 29 30 31
SCLK
Instruction
SI
48H
SO
High_Z
24-Bit Address
3
23 22
2
1
/CS
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
SCLK
Dummy Byte
SI
7
5
4
3
2
1
0
Data Byte 1
SO
Apr
6
7 6
MSB
2022
Rev 1.9
5
4
3
2
1
0
43 / 76
0
Instructions Description
7.3.9
BY25Q64AS
Erase Security Registers (44H)
The BY25Q64AS provides three 256-byte Security Registers which can be erased and
programmed individually. These registers may be used by the system manufacturers to store
security and other important information separately from the main memory array.
See Figure 30, the Erase Security Registers instruction is similar to Sector/Block Erase instruction.
A Write Enable instruction must previously have been executed to set the Write Enable Latch bit.
The Erase Security Registers instruction sequence: /CS goes low sending Erase Security
Registers instruction /CS goes high. /CS must be driven high after the eighth bit of the instruction
code has been latched in otherwise the Erase Security Registers instruction is not executed. As
soon as /CS is driven high, the self-timed Erase Security Registers cycle (whose duration is tSE) is
initiated. While the Erase Security Registers cycle is in progress, the Status Register may be read
to check the value of the Write In Progress (WIP) bit. The Write In Progress (WIP) bit is 1 during
the self-timed Erase Security Registers cycle, and is 0 when it is completed. At some unspecified
time before the cycle is completed, the Write Enable Latch bit is reset. The Security Registers
Lock Bit (LB) in the Status Register can be used to OTP protect the security registers. Once the LB
bit is set to 1, the Security Registers will be permanently locked; the Erase Security Registers
instruction will be ignored.
Address
A23-A16
A15-A12
A11-A8
A7-A0
Security Registers 1
00H
0001
0000
Byte Address
Security Registers 2
00H
0010
0000
Byte Address
Security Registers 3
00H
0011
0000
Byte Address
Figure 30. Erase Security Registers instruction Sequence Diagram
/CS
0
1
2
3 4
5
6
7
8
9
29 30 31
SCLK
Instruction
SI
Apr
2022
24-Bit Address
23 22
44H
Rev 1.9
2
1
0
44 / 76
Instructions Description
BY25Q64AS
7.3.10 Program Security Registers (42H)
See Figure 31, the Program Security Registers instruction is similar to the Page Program
instruction. It allows from 1 to 256 bytes Security Registers data to be programmed. A Write
Enable instruction must previously have been executed to set the Write Enable Latch bit before
sending the Program Security Registers instruction. The Program Security Registers instruction is
entered by driving /CS Low, followed by the instruction code (42H), 3-byte address and at least
one data byte on SI. As soon as /CS is driven high, the self-timed Program Security Registers
cycle (whose duration is tPP) is initiated. While the Program Security Registers cycle is in
progress, the Status Register may be read to check the value of the Write In Progress (WIP) bit.
The Write In Progress (WIP) bit is 1 during the self-timed Program Security Registers cycle, and is
0 when it is completed. At some unspecified time before the cycle is completed, the Write Enable
Latch bit is reset.
If the Security Registers Lock Bit (LB3/LB2/LB1) is set to 1, the Security Registers will be
permanently locked. Program Security Registers instruction will be ignored.
Address
A23-A16
A15-A12
A11-A8
A7-A0
Security Registers 1
00H
0001
0000
Byte Address
Security Registers 2
00H
0010
0000
Byte Address
Security Registers 3
00H
0011
0000
Byte Address
Figure 31. Program Security Registers instruction Sequence Diagram
/CS
0
4
3
2
1
5
6
7
9
8
10
29 30
28
31 32 33 34 35 36 37 38 39
SCLK
Instruction
24-Bit Address
23 22
MSB
42H
SI
21
3
Data Byte 1
1
2
0
7
MSB
6
4
5
2
3
1
0
2079
2078
2077
2076
2075
2074
53 54 55
2073
40 41 42 43 44 45 46 47 48 49 50 51 52
2072
/CS
SCLK
Data Byte 2
SI
7
6
5
4
MSB
Apr
2022
3
2
1
0
7 6
MSB
Data Byte 3
4 3 2
5
Rev 1.9
1
0
7 6
MSB
Data Byte 256
3 2
5 4
45 / 76
1
0
Instructions Description
BY25Q64AS
7.3.11 Enable Reset (66H) and Reset Device (99H)
Because of the small package and the limitation on the number of pins, the BY25Q64AS provides
a software Reset instruction instead of a dedicated RESET pin. Once the software Reset
instruction is accepted, any on-going internal operations will be terminated and the device will
return to its default power-on state and lose all the current volatile settings, such as Volatile Status
Register bits, Write Enable Latch (WEL) status, Program/Erase Suspend status, Continuous Read
Mode bit setting (M7-M0) and Wrap Bit setting (W6-W4).
To avoid accidental reset, both “Enable Reset (66h)” and “Reset (99h)” instructions must be issued
in sequence. Any other commands other than “Reset (99h)” after the “Enable Reset (66h)”
command will disable the “Reset Enable” state. A new sequence of “Enable Reset (66h)” and
“Reset (99h)” is needed to reset the device. Once the Reset command is accepted by the device,
the device will take approximately 30us to reset. During this period, no command will be accepted.
The Enable Reset (66h) and Reset (99h) instruction sequence is shown in Figure 32.
Data corruption may happen if there is an on-going or suspended internal Erase or Program
operation when Reset command sequence is accepted by the device. It is recommended to check
the BUSY bit and the SUS bit in Status Register before issuing the Reset command sequence.
Figure 32. Enable Reset (66h) and Reset (99h) Command Sequence
/CS
0
1
2
3
4
5
6
0
7
1
2
3
4
5
6
SCLK
Instruction
SI
Apr
Instruction
99h
66H
2022
Rev 1.9
46 / 76
7
Instructions Description
BY25Q64AS
7.3.12 Read Serial Flash Discoverable Parameter (5AH)
See Figure 33,The Serial Flash Discoverable Parameter (SFDP) standard provides a consistent
method of describing the functional and feature capabilities of serial flash devices in a standard set
of internal parameter tables. These parameter tables can be interrogated by host system software
to enable adjustments needed to accommodate divergent features from multiple vendors. The
concept is similar to the one found in the Introduction of JEDEC Standard, JESD68 on CFI. SFDP
is a standard of JEDEC Standard No.216.
Figure 33. Read Serial Flash Discoverable Parameter command Sequence Diagram
/CS
0
1
2
3
4
5
6
7
8
9
28 29 30 31
SCLK
Instruction
SI
5AH
SO
High_Z
24-Bit Address
3
23 22
2
1
/CS
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
SCLK
Dummy Byte
SI
7
5
4
3
2
1
0
Data Byte 1
SO
Apr
6
7 6
MSB
2022
Rev 1.9
5
4
3
2
1
0
47 / 76
0
Instructions Description
BY25Q64AS
Table 9. Signature and Parameter Identification Data Values
Description
SFDP Signature
Comment
Add(H)
(Byte)
DW Add
(Bit)
Data
Data
00H
07:00
53H
53H
01H
15:08
46H
46H
02H
23:16
44H
44H
03H
31:24:
50H
50H
Fixed:50444653H
SFDP Minor Revision
Number
Start from 00H
04H
07:00
00H
00H
SFDP Major Revision
Number
Start from 01H
05H
15:08
01H
01H
Number of Parameters
Headers
Start from 00H
06H
23:16
01 H
01 H
Unused
Contains 0xFFH and can
never be changed
07H
31:24
FFH
FFH
ID number (JEDEC)
00H: It indicates a JEDEC
specified header
08H
07:00
00H
00H
Parameter Table Minor
Revision Number
Start from 0x00H
09H
15:08
00H
00H
Parameter Table Major
Revision Number
Start from 0x01H
0AH
23:16
01H
01H
Parameter Table Length (in
double word)
How many DWORDs in the
Parameter table
0BH
31:24
09H
09H
0CH
07:00
30H
30H
0DH
15:08
00H
00H
0EH
23:16
00H
00H
Parameter Table Pointer
(PTP)
First address of JEDEC Flash
Parameter table
Unused
Contains 0xFFH and can
never be changed
0FH
31:24
FFH
FFH
ID Number LSB
(Manufacturer ID)
It is indicates BoyaDevice
manufacturer ID
10H
07:00
68H
68H
Parameter Table Minor
Revision Number
Start from 0x00H
11 H
15:08
00H
00H
Parameter Table Major
Revision Number
Start from 0x01H
12H
23:16
01H
01H
Parameter Table Length (in
double word)
How many DWORDs in the
Parameter table
13H
31:24
03H
03H
14H
07:00
60H
60H
15H
15:08
00H
00H
16H
23:16
00H
00H
17H
31:24
FFH
FFH
Parameter Table Pointer
(PTP)
Contains 0xFFH and can
never be changed
Unused
Apr
First address of Boya Device
Flash Parameter table
2022
Rev 1.9
48 / 76
Instructions Description
BY25Q64AS
Table 10. Parameter Table (0): JEDEC Flash Parameter Tables
Description
Comment
Write Granularity
00: Reserved;
01: 4KB erase;
10: Reserved;
11: not support 4KB erase
0: 1Byte, 1: 64Byte or larger
Write Enable Instruction
Requested for Writing to
Volatile Status Registers
0: Nonvolatile status bit
1: Volatile status bit (BP status
register bit)
Block/Sector Erase Size
Write Enable Opcode Select
for Writing to Volatile Status
Registers
Add(H)
(Byte)
DW
Add
(Bit)
Data
01:00
01b
02
1b
03
0b
30H
0: Use 50H Opcode,
1: Use 06H Opcode,
Note: If target flash status
register is Nonvolatile, then
bits 3 and 4 must be set to
00b.
Contains 111b and can never
be changed
E5H
04
0b
07:05
111b
15:08
20H
16
1b
18:17
00b
19
0b
0=Not support, 1=Support
20
1b
(1 -4-4) Fast Read
0=Not support, 1=Support
21
1b
(1 -1 -4) Fast Read
0=Not support, 1=Support
22
1b
Unused
4KB Erase Opcode
(1 -1 -2) Fast Read
Address Bytes Number used
in addressing flash array
Double Transfer Rate (DTR)
clocking
(1 -2-2) Fast Read
31H
0=Not support, 1=Support
00: 3Byte only,
01: 3 or 4Byte,
10: 4Byte only,
11: Reserved
0=Not support, 1=Support
32H
Unused
Unused
Flash Memory Density
(1 -4-4) Fast Read Number of
Wait states
(1 -4-4) Fast Read Number of
Mode Bits
(1 -4-4) Fast Read Opcode
(1 -1 -4) Fast Read Number of
Wait states
(1 -1 -4) Fast Read Number of
Mode Bits
(1 -1 -4) Fast Read Opcode
(1 -1 -2) Fast Read Number of
Wait states
(1 -1 -2) Fast Read Number of
Mode Bits
(1 -1 -2) Fast Read Opcode
(1 -2-2) Fast Read Number of
Wait states
(1 -2-2) Fast Read Number of
Mode Bits
(1 -2-2) Fast Read Opcode
Apr
2022
00000b: Wait states (Dummy
Clocks) not support
23
1b
33H
31:24
FFH
37H:34H
31:00
39H
00000b: Wait states (Dummy
Clocks) not support
3BH
00000b: Wait states (Dummy
Clocks) not support
3DH
07:05
010b
3FH
F1H
FFH
15:08
EBH
20:16
01000b
23:21
000b
31:24
6BH
04:00
01000b
07:05
000b
15:08
3BH
20:16
00010b
23:21
010b
31:24
BBH
44H
EBH
08H
6BH
08H
3EH
000b: Mode Bits not support
Rev 1.9
00100b
3CH
000b: Mode Bits not support
0000b: Wait states (Dummy
Clocks) not support
04:00
3AH
000b:Mode Bits not support
20H
03FFFFFFH
38H
000b:Mode Bits not support
Data
3BH
42H
49 / 76
BBH
Instructions Description
(2-2-2) Fast Read
BY25Q64AS
0=not support 1=support
Unused
(4-4-4) Fast Read
0=not support 1=support
40H
Unused
00
0b
03:01
111b
04
0b
07:05
111b
EEH
Unused
43H:41H
31:08
0xFFH
0xFFH
Unused
(2-2-2) Fast Read Number
of Wait states
(2-2-2) Fast Read Number
of Mode Bits
(2-2-2) Fast Read Opcode
45H:44H
15:00
0xFFH
0xFFH
20:16
00000b
23:21
000b
47H
31:24
FFH
FFH
49H:48H
15:00
0xFFH
001
00b
0xFFH
Unused
(4-4-4) Fast Read Number
of Wait states
(4-4-4) Fast Read Number
of Mode Bits
(4-4-4) Fast Read Opcode
Sector Type 1 Size
0 0000b: Wait states (Dummy
Clocks) not support
000b: Mode Bits not support
0 0000b: Wait states (Dummy
Clocks) not support
Sector/block size=2^N bytes
0x00b: this sector type don’t exist
Sector/block size=2^N bytes
0x00b: this sector type don’t exist
Sector Type 2 erase
Opcode
Sector Type 3 Size
Sector/block size=2^N bytes
0x00b: this sector type don’t exist
Sector Type 3 erase
Opcode
Sector Type 4 Size
Sector/block size=2^N bytes
0x00b: this sector type don’t exist
Sector Type 4 erase
Opcode
Apr
2022
Rev 1.9
00H
20:16
4AH
000b: Mode Bits not support
Sector Type 1 erase
Opcode
Sector Type 2 Size
46H
44H
23:21
010b
4BH
31:24
EBH
EBH
4CH
07:00
0CH
0CH
4DH
15:08
20H
20H
4EH
23:16
0FH
0FH
4FH
31:24
52H
52H
50H
07:00
10H
10H
51H
15:08
D8H
D8H
52H
23:16
00H
00H
53H
31:24
FFH
FFH
50 / 76
Instructions Description
BY25Q64AS
Table 11. Parameter Table (1): Boya Device Flash Parameter Tables
Description
Vcc Supply Maximum
Voltage
Vcc Supply Minimum
Voltage
HW Reset# pin
HW Hold# pin
Deep Power Down
Mode
SW Reset
SW Reset Opcode
Program
Suspend/Resume
Erase
Suspend/Resume
Unused
Wrap-Around Read
mode
Wrap-Around Read
mode Opcode
Wrap-Around Read
data length
Individual block lock
Individual block lock
bit(Volatile/Nonvolatil
e)
Individual block lock
Opcode
Individual block lock
Volatile protect bit
default protect status
Secured OTP
Comment
Add(H)
(Byte)
DW Add
(Bit)
61H:60H
63H:62H
Data
Data
15:00
3600H
3600H
31:16
2700H
2700H
00
0b
0=not support 1=support
01
1b
0=not support 1=support
02
1b
0=not support 1=support
Should be issue Reset
Enable(66H)before Reset cmd.
03
1b
11:04
99H
0=not support 1=support
12
1b
0=not support 1=support
13
1b
14
1b
15
1b
66H
23:16
77H
77H
67H
31:24
64H
64H
00
0b
01
0b
09:02
FFH
10
0b
2000H=2.000V
2700H=2.700V
3600H=3.600V
1650H=1.650V
2250H=2.250V
2350H=2.350V
2700H=2.700V
0=not support 1=support
65H:64H
0=not support 1=support
08H:support 8B wrap-around
read
16H:8B&16B
32H:8B&16B&32B
64H:8B&16B&32B&64B
0=not support 1=support
0=Volatile 1=Nonvolatile
0=protect 1=unprotect
6BH:68H
0=not support 1=support
11
1b
Read Lock
0=not support 1=support
12
0b
Permanent Lock
0=not support 1=support
13
1b
Unused
15:14
11b
Unused
31:16
FFFFH
Apr
2022
Rev 1.9
51 / 76
F99EH
EBFCH
FFFFH
Instructions Description
BY25Q64AS
7.4 Program and Erase Instructions
7.4.1
Page Program (02H)
The Page Program instruction is for programming the memory. A Write Enable instruction must
previously have been executed to set the Write Enable Latch bit before sending the Page Program
instruction.
See Figure 34, the Page Program instruction is entered by driving /CS Low, followed by the
instruction code, 3-byte address and at least one data byte on SI. If the 8 least significant address
bits (A7-A0) are not all zero, all transmitted data that goes beyond the end of the current page are
programmed from the start address of the same page (from the address whose 8 least significant
bits (A7-A0) are all zero). /CS must be driven low for the entire duration of the sequence. The
Page Program instruction sequence: /CS goes low-> sending Page Program instruction ->3-byte
address on SI ->at least 1 byte data on SI-> /CS goes high.
If more than 256 bytes are sent to the device, previously latched data are discarded and the last
256 data bytes are guaranteed to be programmed correctly within the same page. If less than 256
data bytes are sent to device, they are correctly programmed at the requested addresses without
having any effects on the other bytes of the same page. /CS must be driven high after the eighth
bit of the last data byte has been latched in; otherwise the Page Program instruction is not
executed.
As soon as /CS is driven high, the self-timed Page Program cycle (whose duration is tPP) is
initiated. While the Page Program cycle is in progress, the Status Register may be read to check
the value of the Write in Progress (WIP) bit. The Write in Progress (WIP) bit is 1 during the
self-timed Page Program cycle, and is 0 when it is completed. At some unspecified time before the
cycle is completed, the Write Enable Latch bit is reset.
A Page Program instruction applied to a page which is protected by the Block Protect (BP4, BP3,
BP2, BP1, BP0) bits (see Table 5&6) is not executed.
Figure 34. Page Program Sequence Diagram
/CS
0
4
3
2
1
5
6
7
8
9
10
29 30
28
31 32 33 34 35 36 37 38 39
SCLK
Instruction
24-Bit Address
23 22 21
MSB
02H
SI
3
Data Byte 1
1
2
0
7 6
MSB
4
5
2
3
1
0
2079
2078
2077
2076
2075
2074
2073
40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
2072
/CS
SCLK
Data Byte 2
7
SI
6
MSB
Apr
2022
5
4
3
2
1
0
7 6
MSB
Data Byte 3
5 4 3 2
Rev 1.9
1
0
7 6
MSB
Data Byte 256
3 2
5 4
52 / 76
1
0
Instructions Description
7.4.2
BY25Q64AS
Quad Page Program (32H)
The Quad Page Program instruction is for programming the memory using for pins: IO0, IO1, IO2
and IO3. To use Quad Page Program the Quad enable in status register Bit9 must be set (QE=1).
A Write Enable instruction must previously have been executed to set the Write Enable Latch bit
before sending the Page Program instruction. The Quad Page Program instruction is entered by
driving /CS Low, followed by the command code (32H), three address bytes and at least one data
byte on IO pins.
The instruction sequence is shown in Figure 35, .If more than 256 bytes are sent to the device,
previously latched data are discarded and the last 256 data bytes are guaranteed to be
programmed correctly within the same page. If less than 256 data bytes are sent to device, they
are correctly programmed at the requested addresses without having any effects on the other
bytes of the same page. /CS must be driven high after the eighth bit of the last data byte has been
latched in; otherwise the Quad Page Program instruction is not executed.
As soon as /CS is driven high, the self-timed Quad Page Program cycle (whose duration is tPP) is
initiated. While the Quad Page Program cycle is in progress, the Status Register may be read to
check the value of the Write in Progress (WIP) bit. The Write In Progress (WIP) bit is 1 during the
self-timed Quad Page Program cycle, and is 0 when it is completed. At some unspecified time
before the cycle is completed, the Write Enable Latch bit is reset. A Quad Page Program
instruction applied to a page which is protected by the Block Protect (BP4, BP3, BP2, BP1, BP0)
bits (see Table 5&6) is not executed
Figure 35. Quad Page Program Sequence Diagram
/CS
0
1
2
3
4
5
6
7
30 31 32 33 34 35 36 37 38 39
8
SCLK
Instruction
SI
(IO0)
32H
SO
(IO1)
High_Z
WP
(IO2)
High_Z
HOLD
(IO3)
High_Z
24-bits address
23 22
0
1
4
0
4
0
4
0
4
0
5
1
5
1
5
1
5
1
6
2
6
2
6
2
6
2
7
3
7
3
7
3
7
3
Byte1
Byte2
/CS
SCLK
40 41 42
43 44 45 46
47 48
535 536 537 538 539 540 541 542 543
SI
(IO0)
4
0
4
0
4
0
4
0
4
0
4
0
4
0
4
0
SO
(IO1)
5
1
5
1
5
1
5
1
5
1
5
1
5
1
5
1
WP
(IO2)
6
2
6
2
6
2
6
2
6
2
6
2
6
2
6
2
7 3
Byte 5
7
3
7
3
7
3
7
3
7
3
7
3
7
3
High_Z
High_Z
High_Z
High_Z
HOLD
(IO3)
Apr
Byte 6
2022
Byte 253
Rev 1.9
Byte 256
53 / 76
Instructions Description
7.4.3
BY25Q64AS
Fast Page Program (F2H)
The Fast Page Program instruction is used to program the memory. A Write Enable instruction
must previously have been executed to set the Write Enable Latch bit before sending the Page
Program instruction.
The Fast Page Program instruction is entered by driving /CS Low, followed by the instruction code,
3-byte address and at least one data byte on SI. If the 8 least significant address bits (A7-A0) are
not all zero, all transmitted data that goes beyond the end of the current page are programmed
from the start address of the same page (from the address whose 8 least significant bits (A7-A0)
are all zero). /CS must be driven low for the entire duration of the sequence.
The Fast Page Program instruction sequence: /CS goes low ->sending Page Program instruction->
3-byte address on SI-> at least 1 byte data on SI ->/CS goes high.
The command sequence is shown in Figure 36, If more than 256 bytes are sent to the device,
previously latched data are discarded and the last 256 data bytes are guaranteed to be
programmed correctly within the same page. If less than 256 data bytes are sent to device, they
are correctly programmed at the requested addresses without having any effects on the other
bytes of the same page. /CS must be driven high after the eighth bit of the last data byte has been
latched in; otherwise the Fast Page Program instruction is not executed.
As soon as /CS is driven high, the self-timed Page Program cycle (whose duration is tPP) is
initiated. While the Page Program cycle is in progress, the Status Register may be read to check
the value of the Write in Progress (WIP) bit. The Write In Progress (WIP) bit is 1 during the
self-timed Page Program cycle, and is 0 when it is completed. At some unspecified time before the
cycle is completed, the Write Enable Latch bit is reset.
A Fast Page Program instruction applied to a page which is protected by the Block Protect (BP4,
BP3, BP2, BP1, BP0) bits (see Table 5&6) is not executed.
Figure 36.Fast Page Program Sequence Diagram
/CS
0
4
3
2
1
5
6
7
9
8
10
29 30
28
31 32 33 34 35 36 37 38 39
SCLK
Instruction
SI
Data Byte 1
24-Bit Address
23 22 21
MSB
F2H
3
1
2
0
7 6
MSB
4
5
2
3
1
0
2079
2078
2077
2076
2075
2074
2073
40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
2072
/CS
SCLK
Data Byte 2
7
SI
6
MSB
Apr
2022
5
4
3
2
1
0
7 6
MSB
Data Byte 3
4 3 2
5
Rev 1.9
1
0
7 6
MSB
Data Byte 256
3 2
5 4
54 / 76
1
0
Instructions Description
7.4.4
BY25Q64AS
Sector Erase (20H)
The Sector Erase instruction is for erasing the all data of the chosen sector. A Write Enable
instruction must previously have been executed to set the Write Enable Latch bit. The Sector
Erase instruction is entered by driving /CS low, followed by the instruction code, and 3-address
byte on SI. Any address inside the sector is a valid address for the Sector Erase instruction. /CS
must be driven low for the entire duration of the sequence.
See Figure 37, The Sector Erase instruction sequence: /CS goes low-> sending Sector Erase
instruction-> 3-byte address on SI ->/CS goes high. /CS must be driven high after the eighth bit of
the last address byte has been latched in; otherwise the Sector Erase instruction is not executed.
As soon as /CS is driven high, the self-timed Sector Erase cycle (whose duration is tSE) is initiated.
While the Sector Erase cycle is in progress, the Status Register may be read to check the value of
the Write in Progress (WIP) bit. The Write in Progress (WIP) bit is 1 during the self-timed Sector
Erase cycle, and is 0 when it is completed. At some unspecified time before the cycle is completed,
the Write Enable Latch bit is reset. A Sector Erase instruction applied to a sector which is
protected by the Block Protect (BP4, BP3, BP2, BP1, BP0) bits (see Table 5&6) is not executed.
Figure 37. Sector Erase Sequence Diagram
/CS
0
1
2
3 4
5
6
7
8
9
29 30 31
SCLK
Instruction
SI
Apr
2022
24-Bit Address
23 22
20H
Rev 1.9
2
1
0
55 / 76
Instructions Description
7.4.5
BY25Q64AS
32KB Block Erase (52H)
The 32KB Block Erase instruction is for erasing the all data of the chosen block. A Write Enable
instruction must previously have been executed to set the Write Enable Latch bit. The 32KB Block
Erase instruction is entered by driving /CS low, followed by the instruction code, and 3-byte
address on SI. Any address inside the block is a valid address for the 32KB Block Erase
instruction. /CS must be driven low for the entire duration of the sequence.
See Figure 38, the 32KB Block Erase instruction sequence: /CS goes low ->sending 32KB Block
Erase instruction ->3-byte address on SI ->/CS goes high. /CS must be driven high after the eighth
bit of the last address byte has been latched in; otherwise the 32KB Block Erase instruction is not
executed. As soon as /CS is driven high, the self-timed Block Erase cycle (whose duration is tBE)
is initiated. While the Block Erase cycle is in progress, the Status Register may be read to check
the value of the Write in Progress (WIP) bit. The Write In Progress (WIP) bit is 1 during the
self-timed Block Erase cycle, and is 0 when it is completed. At some unspecified time before the
cycle is completed, the Write Enable Latch bit is reset. A 32KB Block Erase instruction applied to a
block which is protected by the Block Protect (BP4, BP3, BP2, BP1, BP0) bits (see Table 5&6) is
not executed.
Figure 38. 32KB Block Erase Sequence Diagram
/CS
0
1
2
3 4
5
6
7
8
9
29 30 31
SCLK
Instruction
SI
Apr
2022
24-Bit Address
23 22
52H
Rev 1.9
2
1
0
56 / 76
Instructions Description
7.4.6
BY25Q64AS
64KB Block Erase (D8H)
The 64KB Block Erase instruction is for erasing the all data of the chosen block. A Write Enable
instruction must previously have been executed to set the Write Enable Latch bit. The 64KB Block
Erase instruction is entered by driving /CS low, followed by the instruction code, and 3-byte
address on SI. Any address inside the block is a valid address for the 64KB Block Erase
instruction. /CS must be driven low for the entire duration of the sequence.
See Figure 39, the 64KB Block Erase instruction sequence: /CS goes low sending 64KB Block
Erase instruction 3-byte address on SI /CS goes high. /CS must be driven high after the eighth bit
of the last address byte has been latched in; otherwise the 64KB Block Erase instruction is not
executed. As soon as /CS is driven high, the self-timed Block Erase cycle (whose duration is tBE)
is initiated. While the Block Erase cycle is in progress, the Status Register may be read to check
the value of the Write in Progress (WIP) bit. The Write in Progress (WIP) bit is 1 during the
self-timed Block Erase cycle, and is 0 when it is completed. At some unspecified time before the
cycle is completed, the Write Enable Latch bit is reset. A 64KB Block Erase instruction applied to a
block which is protected by the Block Protect (BP4, BP3, BP2, BP1, BP0) bits (see Table 5&6) is
not executed.
Figure 39 64KB Block Erase Sequence Diagram
/CS
0
1
2
3 4
5
6
7
8
9
29 30 31
SCLK
Instruction
SI
Apr
2022
24-Bit Address
23 22
D8H
Rev 1.9
2
1
0
57 / 76
Instructions Description
7.4.7
BY25Q64AS
Chip Erase (60/C7H)
The Chip Erase instruction sets all memory within the device to the erased state of all 1s (FFh). A
Write Enable instruction must be executed before the device will accept the Chip Erase Instruction
(Status Register bit WEL must equal 1). The instruction is initiated by driving the /CS pin low and
shifting the instruction code “C7h” or “60h”. The Chip Erase instruction sequence is shown in
Figure 40.
The /CS pin must be driven high after the eighth bit has been latched. If this is not done the Chip
Erase instruction will not be executed. After /CS is driven high, the self-timed Chip Erase
instruction will commence for a time duration of tCE. While the Chip Erase cycle is in progress, the
Read Status Register instruction may still be accessed to check the status of the WIP bit.
The WIP bit is a 1 during the Chip Erase cycle and becomes a 0 when finished and the device is
ready to accept other Instructions again. After the Chip Erase cycle has finished the Write Enable
Latch (WEL) bit in the Status Register is cleared to 0. The Chip Erase instruction is executed only
if all Block Protect (BP2, BP1, and BP0) bits are 0. The Chip Erase instruction is ignored if one or
more sectors are protected.
Figure 40. Chip Erase Sequence Diagram
/CS
0
1
2
3
4
5
6
7
SCLK
Instruction
SI
SO
Apr
2022
60/C7H
High_Z
Rev 1.9
58 / 76
Instructions Description
7.4.8
BY25Q64AS
Erase / Program Suspend (75H)
The Erase/Program Suspend instruction allows the system to interrupt a Sector or Block Erase
operation, then read from or program data to any other sector/block which is not in the same big
block(4Mbit). The Erase/Program Suspend instruction also allows the system to interrupt a Page
Program operation and then read from any other page or erase any other sector or block. The
Erase/Program Suspend instruction sequence is shown in Figure 41
The Write Status Registers instruction (01h) and Erase instructions (20h, 52h, D8h, C7h, 60h, 44h)
are not allowed during Erase Suspend. Erase Suspend is valid only during the Sector or Block
erase operation. If written during the Chip Erase operation, the Erase Suspend instruction is
ignored. The Write Status Registers instruction (01h), and Program instructions (02h, 42h, 32h,
F2h) are not allowed during Program Suspend. Program Suspend is valid only during the Page
Program operation. Write status register operation can't be suspended.
Figure 41. Erase/Program Suspend Command Sequence
/CS
0
1
2
3
4
5
6
0
7
1
2
3
4
5
6
7
SCLK
Instruction
SI
tSUS
Instruction During Suspend
75H
Table 12, Readable or Erasable Area of Memory While a Program Operation is Suspended
Readable or Erasable Region
Of Memory Array
All but the Page being programmed
All but the Page being programmed
All but the Page being programmed
Suspended operation
Page Program
Fast Page Program
Quad Page Program
Note1: If read the page being programmed, read instruction will be executed, but the data output
may be wrong.
Note2: If erase a sector/block that including the page being programmed, the erase instruction
will be ignored.
Table 13, Readable or Programmable Area of Memory While an Erase Operation is
Suspended
Suspended operation
Sector Erase(4KB)
Block Erase(32KB)
Block Erase(64KB)
Readable or Programmable Region
Of Memory Array
All but the Big Block(4Mbit) being Erased
All but the Big Block(4Mbit) being Erased
All but the Big Block(4Mbit) being Erased
Note3: If read data from the same Big Block(4Mbit), read instruction will be executed, but the
data output may be wrong.
Note4: If program a page in the same sector/block, the program instruction will be ignored.
Note5:
Apr
If program a page in other sector/block in the same big block(4Mbit), the program
instruction will be executed, but it may be timeout, or the data after program may be
wrong.
2022
Rev 1.9
59 / 76
Instructions Description
7.4.9
BY25Q64AS
Erase / Program Resume (7AH)
The Erase/Program Resume instruction “7Ah” must be written to resume the Sector or Block
Erase operation or the Page Program operation after an Erase/Program Suspend. The Resume
instruction “7AH” will be accepted by the device only if the SUS bit in the Status Register equals to
1 and the WIP bit equals to 0.
After the Resume instruction is issued the SUS bit will be cleared from 1 to 0 immediately, the WIP
bit will be set from 0 to 1 within 200 ns and the Sector or Block will complete the erase operation or
the page will complete the program operation. If the SUS bit equals to 0 or the WIP bit equals to 1,
the Resume instruction “7Ah” will be ignored by the device. The Erase/Program Resume
instruction sequence is shown in Figure 42
Figure 42. Erase/Program Resume Command Sequence
/CS
0
1
2
3
4
5
6
7
SCLK
Instruction
Apr
2022
SI
7AH
SO
High_Z
Rev 1.9
60 / 76
Electrical Characteristics
BY25Q64AS
8. Electrical Characteristics
8.1 Absolute Maximum Ratings
PARAMETERS
SYMBOL
Supply Voltage
VCC
Voltage Applied to Any Pin
VIO
Transient Voltage on any Pin
VIOT
Storage Temperature
TSTG
Electrostatic Discharge Voltage
VESD
CONDITIONS
RANGE
UNIT
–0.5 to 4
V
Relative to Ground
–0.5 to 4
V
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