UR5HC418

DeskCoderTM UR5HC418 AT / PS/2 - Compatible Keyboard Encoder HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODERTM FAMILY DESCRIPTION The DeskCoderTM keyboard encoder functions as a versatile, low-power desktop keyboard encoder, while providing two bi-directional channels for communication with a BIOS-compatible system as well as any optional keyboard-compatible devices, such as a 101/102/104 desktop keyboard, OCR, barcode reader, etc. The DeskCoderTM fully supports the IBM standard keyboard communication protocol; each key press generates one of the scan codes designated in the IBM Technical Reference Manuals. The keyboard encoder handles the scanning, debounce, and encoding of 128 keys organized on an 8 x 16 matrix. In addition to the system’s keyboard communication port, the UR5HC418 provides a fully functional keyboard input port that can be used by a standard 101/102/104 keyboard or another 8042-compatible device, such as an external numeric keypad, an OCR, or a bar-code reader. Input from both the matrix and the external device is multiplexed and presented to the system as if it were coming from a single source. The DeskCoderTM is ideal for use in low-power, low-cost and highreliability AT / PS/2 - compatible keyboard designs. Note: A version of the IC that supports the PC/XT protocol is also available. Contact Semtech for more information. FEATURES • Interfaces contact switch matrix keyboards to a BIOS-compatible system • Single IC desktop keyboard encoder • Provides interface for an external keyboard/keypad or other 8042compatible devices • AT / PS/2 - compatible APPLICATIONS • Desktop computers • Instrumentation • Industrial keyboards PIN ASSIGNMENTS • Point of sales terminals • Public information kiosks • Implements all functions of a 101/102/104 keyboard • Low-power HCMOS microcontroller, suitable for 3-volt battery-operated systems • Available in DIP, PLCC and QFP packages • Custom versions available in small or large quantities 6 RP KD KC EKC EKD CL C0 C1 C2 C3 C4 7 1 R6 NL VX VXA _IRQ _RESET VCC OSCI OSC0 EKC1 R7A 40 39 _RESET _IRQ VX NL R6 RP KD KC EKC EKD CL C0 C1 C2 C3 C4 C5 C6 C7 VSS/GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 VCC OSCI OSCO EKC1 R7 SL R5 R4 R3 R2 R1 R0 C8 C9 C10 C11 C12 C13 C14 C15 12 PLCC 34 17 18 23 29 28 R7 SL R5 R4 R3 R2 R1 R0 C8 C9 C10 DIP NL VX _IRQ _RESET NC NC VCC OSCI OSCO EKC1 R7 C4A C5 C6 C7 VSS/GND NC C15 C14 C13 C12 C11 R6 RP KD KC EKC EKD CL C0 C1 C2 C3 1 QFP NL R5 R4 R3 R2 R1 R0 C8 C9 C10 C11 DeskCoder and KeyCoder are trademarks of Semtech Corporation. All other trademarks belong to their respective companies. Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 1 www.semtech.com C4 C5 C6 C7 NC VSS/GND C15 C14 C13 C12 NC ORDERING CODE Package options 40-pin, Plastic DIP 44-pin, Plastic PLCC 44-pin, Plastic QFP Pitch in mm’s 2.54 1.27 0.8 TA = -40°C to +85°C UR5HC418-P UR5HC418-FN UR5HC418-FB FUNCTIONAL DIAGRAM NL/CL/SL 3 Data Buffer Status LEDs Row Data Inputs EKC1 Interrupt Control Column Select Ouputs 16 8 R0-R7 C0-C15 Keyboard Encoder KC KD PC Communication Channel 16-Bit Timer Mode Control 8042 Emulation (External Keyboard) Communication Channel EKC EKD KT DRV Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 2 www.semtech.com FUNCTIONAL DESCRIPTION The DeskCoder consists functionally of seven major sections shown in the functional diagram on the previous page: the keyboard encoder, a 16-bit timer, the mode control unit, the data buffer, the interrupt control, the PC communication channel and the 8042 emulation channel. All sections communicate with each other and operate concurrently. TM PIN DEFINITIONS Mnemonic VCC VSS (GND) OSCI OSCO _RESET EKC1 DIP PLCC 40 44 20 22 39 43 38 42 1 1 37 41 QFP 38 17 37 36 41 35 Type I I I O I I Name and Function Power Supply: +5V Ground Oscillator input Oscillator output Reset: apply 0V to provide orderly start-up External Keyboard Clock 1:connects to external keyboard clock line and is used to generate an interrupt for every clock line transmission Tie to VCC Tie to VCC Tie to VCC Keyboard Clock: connects to PC keyboard port clock data line Keyboard Data: connects to PC port data line External Keyboard Data: connect to external keyboard data line External Keyboard Clock: connects to external keyboard clock line Interrupt Line: reserved for low power applications Row Data Inputs KEYBOARD ENCODER The controller continuously scans a keyboard organized as an 8 row by 16 column matrix for a maximum of 128 keys. Smaller-size keyboards are supported provided that all unused row lines are pulled to Vcc. The controller selects one of the 16 column lines (C0-C15) every 512 microseconds and then reads the row data lines (R0-R7). A key closure is detected as a zero in the corresponding position of the matrix. A complete scan cycle for the entire keyboard takes approximately 9.2 mS. Each key found pressed is debounced for a period of 20 mS. Once the key is verified, the corresponding key code(s) are loaded into the transmit buffer of the PC communication channel. VX VXA RP KC KD EKD EKC _IRQ R0-R5 R6 R7 R7A C0-C4 C5-C7 C8-C15 C4A CL NL SL NC 3 6 8 7 10 9 2 29-34 5 36 12-16 17-19 28-21 4 3 7 9 8 11 10 2 32-37 6 39 40 13-17 19-21 31-24 18 12 5 38 23 43 2 4 3 6 5 42 27-32 1 34 8-12 13-15 26-23 21-18 7 44 33 39-40 16, 22 I I I I/O I/O I/O I/O I/O I I I I O O O O O O O O Column Select Outputs: select one of 16 columns 11 4 35 Caps Lock LED Num Lock LED Scroll Lock LED No Connects: these pins are unused Note: An underscore before a pin mnemonic denotes an active low signal. KEYBOARD ENCODER, (CON’T) Status LED indicators The controller provides an interface for three LED shift status indicators. All three pins are active low to indicate the status of the host system (Num Lock, Caps Lock and Scroll Lock) and are set by the system. Scan Code Table Sets The UR5HC418 supports all three scan code table sets. Scan code table set 3 allows the user to program individual key attributes such as make/break and Typematic or single-touch action. For more information, refer to the IBM Technical Reference Manuals. Custom scan code tables, including macros, are also available. Switch Matrix Encoding Each matrix location is programmed to represent either a single key or a key combination of the IBM 101/102/104 standard keyboard. Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 3 www.semtech.com SPECIAL HANDLING MODE CONTROL Connection of External Device The DeskCoderTM detects the presence of an external device. If an external keyboard or other device is not connected at power-on and is connected at a later time, the encoder proceeds with the normal reset routine in order to properly initialize the external device. After communication has been established, the encoder continues to check for the presence of the external device. If the device is disconnected at a later time, the encoder becomes aware of it. If a subsequent connection takes place, the controller re-initiates a reset sequence. This unique feature allows the user to connect or disconnect an external device at any time without having to reset the system. N-Key Rollover In this mode, the code(s) corresponding to each key press are transmitted to the host system as soon as that key is debounced, independently of the release of other keys. If a key is defined to be Typematic, the corresponding make code(s) are transmitted while the key is held pressed. When a key is released, the corresponding break code(s) are then transmitted to the host system. If the released key happens to be the most recently pressed, then Typematic action is terminated. There is no limitation in the number of keys that can be held pressed at the same time. However, two or more key closures, occurring within a time interval less than five mS, set an error flag and are not processed. This procedure protects against effects of accidental key presses. “Ghost” Keys In any scanned contact switch matrix, whenever three keys defining a rectangle on the switch matrix are pressed at the same time, a fourth key positioned on the fourth corner of the rectangle is sensed as being pressed. This is known as the “ghost” or “phantom” key problem. Although the problem cannot be totally eliminated without using external hardware, there are methods to neutralize its negative effects for most practical applications. Keys that are intended to be used in combinations or are likely to be pressed at the same time by a fast typist (i.e., keys located in adjacent positions on the keyboard) should be placed in the same row or column of the matrix whenever possible. Shift Keys (Shift, Alt, Ctrl) should not reside in the same row (or column) with any other keys. The DeskCoderTM has built-in mechanisms to detect the presence of a “ghost” key, thus eliminating the necessity of external hardware. Actual key presses Shift Status LEDs Shift Status LEDs (Num Lock, Caps Lock and Scroll Lock) indicate the status of the system and are controlled by commands sent from the system. Set/Reset Status Indicator Commands from the system will be executed both by the external keyboard and the scanned matrix. For example, if the user presses the Caps Lock Key on either keyboard, the Caps Lock LED will be effected on both keyboards. The LED status indicators are properly set after each new connection of an external keyboard. “Ghost” Key Figure 1: “Ghost” or “Phantom” Key Problem Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 4 www.semtech.com 8042 EMULATION CHANNEL The DeskCoder fully emulates a system’s keyboard port, available to a standard 84/85/101/102 external keyboard or other 8042-compatible device. Communication with a keyboard-compatible device is accomplished by clock and data lines via EKC and EKD pins, respectively. A third pin, EKC1 that connects to the clock line, interrupts the controller whenever the external device initiates a communication session. When power is first applied, the controller proceeds with the standard reset sequence with the external device. Data and commands initiated from the external device are buffered in the controller’s FIFO along with data from the scanned matrix, and then are presented to the system as if they were coming from a single source. Once they are acknowledged, commands and data from the system are then transmitted to the external device. TM PC COMMUNICATION The DeskCoderTM implements all the standard functions of communication with a BIOScompatible PC/XT or AT/PS/2 host system. Two lines, KC and KD, provide bi-directional clock and data signals. In addition, the DeskCoderTM supports all commands from and to the system, as described in the IBM Technical Reference Manuals. The following table shows the commands that the system may send and their values in hexadecimal. Command Hex Value Set/Reset Status ED Indicators Echo EE Invalid Command EF Select Alternate F0 Scan Codes Invalid Command F1 Read ID F2 Set Typematic F3 Rate/Delay Enable F4 Default Disable F5 Set Default F6 Set All Keys Typematic F7 Make/Break F8 Make F9 Typematic/Make/Break FA Set Key Type Typematic FB Make/Break FC Make FD Resend FE Reset FF Table 2: Keyboard Commands from the System (AT / PS/2 protocol) The following table shows the commands that the keyboard may send to the system. Command Key Detection Error/Overrun Keyboard ID BAT Completion Code BAT Failure Code Echo Acknowledge (Ack) Resend Key Detection Error/Overrun Hex Value 00* 83AB AA FC EE FA FE FF** *Code Sets 2 and 3 **Code Set 1 Table 3: Keyboard Commands to the System (AT/PS/2 protocol) When an external keyboard is connected, commands from the system are also directed to the external keyboard. Presence or absence of an external device does not affect the normal operation of the UR5HC418. These commands are supported in the AT / PS/2 protocol and can be sent to the keyboard at any time. Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 5 www.semtech.com STANDARD KEY MAP Columns (C0–C15) 7 8 9 Ins Del LArr 0 1 Esc 2 Tab 3 LAlt 4 5 6 10 DnArr 11 LSft 12 RArr 13 Pad / 14 15 0 1 LCtrl Space LWin ` (BkQt) X C (per) Pad 9 Pad Ent RCtrl F1 Z RAlt . / Key45* UpArr RSft End Pad * Pad 8 Pad - 2 3 Rows (R0–R7) 1 CpsLk V B N M (com) J , , (appos) K L Ent PgDn Pad 1 Pad 7 Win App F2 A S D F ; PgUp Pad 2 F11 RWin 4 2 3 4 T Y U I O P BkSpc Pad 3 F12 5 F4 F5 F6 F7 F8 F9 F10 NumLk ScrlLk PntScr Pad 4 Pad 0 F3 5 6 7 8 9 6 Q W E R G H 0 (dash) [ ] = Pause Pad 5 Pad . \ Home Pad 6 Pad + 7 *Note: Key 45 = Additional European Key KEYBOARD LAYOUT, DEFAULT The UR5HC418 implements a standard keyboard layout. (Key numbering of a standard 101/102/104 keyboard is shown.) ES C SF1 SF2 SF3 SF4 SF5 SF6 SF7 SF8 SF9 SF10 SF11 SF12 Pri nt Sc r. Sc rol l Loc k Pa us e ~ ` ! 1 @ 2 # 3 $ 4 % 5 ^ 6 & 7 * 8 ( 9 ) 0 _ { [ : ; > . ? / " ' + = } ] B a c ks pa c e Ins e rt Hom e Pa ge Up Num Loc k / 8 0 5 0 2 0 * - Ta b Q W E R T Y U I O P ESC De l e t e End Pa ge Down 7 0 4 0 9 0 + Ca p s Lock A S D F G H J K > , L 6 0 3 0 Enter Sh i f t Z X C V B N M Shi ft | \ 1 0 0 In s Ctr l Al t Space Al t C t rl . De l Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 6 www.semtech.com IMPLEMENTATION NOTES FOR THE UR5HC418 The following notes pertain to the suggested schematics found on the next pages. The built-in oscillator on the UR5HC418 requires the attachment of the 4.00 MHz ceramic resonators with built-in load capacitors. You can use either an AVX, part number PBRC-1.00 BR; or a Murata part number CSTCC4.00MG ceramic resonator. It may also be possible to operate with the 4.00 MHz crystal, albeit with reduced performance. Due to their high Q, the crystal oscillator circuits start-up slowly. Since the DeskCoderTM constantly switches the clock on and off, it is important that a ceramic resonator is used (it starts up much quicker than the crystal). Resonators are also less expensive than crystals. Also, if crystal is attached, two load capacitors (33pF to 47pF) should be added, a capacitor between each side of the crystal and ground. In both cases, using ceramic resonator with built-in load capacitors, or crystal with external load capacitors, a feedback resistor of one MegaOhm should be connected between OSCin and OSCout. Troubleshoot the circuit by looking at the output pin of the oscillator. If the voltage it half-way between supply and ground (while the oscillator should be running) --- the problem is with the load caps / crystal. If the voltage it all the way at supply or ground (while the oscillator should be running) --- there are shorts on the PCB. Note: when the oscillator is intentionally turned off, the voltage on the output pin of the oscillator is high (at the supply rail). Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 7 www.semtech.com SUGGESTED INTERFACING FOR THE UR5HC418 Vcc Vcc 100K STATUS LEDs 1uF GND Vcc 1 RST Vcc 44 Vcc 5 NL 12 CL SL C15 C14 C13 C12 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0 C4A R7A R7 R6 R5 R4 R3 R2 R1 R0 24 25 26 27 28 29 30 31 21 20 19 17 16 15 14 13 18 40 39 6 37 36 35 34 33 32 CS15 CS14 CS13 CS12 CS11 CS10 CS9 CS8 CS7 CS6 CS5 CS4 CS3 CS2 CS1 CS0 TO SWITCH MATRIX RDAT7 RDAT6 RDAT5 RDAT4 RDAT3 RDAT2 RDAT1 RDAT0 38 4.7K 4.7K EKDAT EKBCLK 2K 2K 11 10 41 Vcc 2 IRQ KC KD PC KEYBOARD PORT COMMUNICATIONS ROW DATA INPUTS EKD EKC EKC1 8042 EMULATION PORT COLUMN SELECT OUTPUTS 44 Pin PLCC KBCLK KBDAT 4 X 47pF 9 8 GND 23 NC OSCI LINE INTERFACE 43 1 MEG OSCO 42 Vss 22 GND RP VXA 7 3 VX 4 Vcc Vcc Vcc 4.00 MHz Vcc 8 x 22K GND Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 8 www.semtech.com ALTERNATE SCHEMATIC FOR THE UR5HC418 WITH RESET CIRCUIT Vcc 2 Telecom TC54VC4502ECB 3 Vcc GND Vcc 1 RST 44 Vcc 5 NL Vcc STATUS LEDs 1 12 CL SL 38 4.7K 4.7K EKDAT EKBCLK 2K 2K 11 10 41 Vcc 2 IRQ KC KD PC KEYBOARD PORT COMMUNICATIONS ROW DATA INPUTS EKD EKC EKC1 8042 EMULATION PORT COLUMN SELECT OUTPUTS 44 Pin PLCC KBCLK KBDAT 4 X 47pF 9 8 C15 C14 C13 C12 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0 C4A R7A R7 R6 R5 R4 R3 R2 R1 R0 24 25 26 27 28 29 30 31 21 20 19 17 16 15 14 13 18 40 39 6 37 36 35 34 33 32 CS15 CS14 CS13 CS12 CS11 CS10 CS9 CS8 CS7 CS6 CS5 CS4 CS3 CS2 CS1 CS0 TO SWITCH MATRIX RDAT7 RDAT6 RDAT5 RDAT4 RDAT3 RDAT2 RDAT1 RDAT0 GND 23 NC OSCI LINE INTERFACE 43 1 MEG OSCO 42 Vss 22 GND RP VXA 7 3 VX 4 Vcc Vcc Vcc 4.00 MHz Vcc 8 x 22K GND Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 9 www.semtech.com MECHANICALS FOR THE UR5HC418-P 40 21 B L 1 20 A C J N M F K Seating Plane Notes: 1. Positional tolerance of leads (D) shall be within 0.25 mm (0.010) at maximum material condition, in relation to the seating plane and each other. 2. Diminsion L is to the center of the leads when the leads are formed parallel. 3. Dimension B does not include mold flash. H G D MILLIMETERS INCHES DIM A B C D F G H J K L M N MIN MAX 51.69 52.45 13.72 14.22 3.94 5.08 0.36 0.56 1.02 1.52 2.54 BSC 1.65 2.16 0.20 0.38 2.92 3.43 15.24 BSC 00 15 0 0.51 1.02 MIN MAX 2.035 2.065 0.540 0.560 0.155 0.200 0.014 0.022 0.040 0.060 0.100 BSC 0.065 0.085 0.008 0.015 0.015 0.135 0.600 BSC 00 15 0 0.020 0.040 Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 10 www.semtech.com MECHANICALS FOR THE UR5HC418-FN N Y BRK D L 44 Leads PLCC M B 0.18 (0.007) M T N S -P S L S -M S U W Z1 D 0.18 (0.007) M T N S -P S L S -M S Note 1 (Note 1) 44 1 P V A Z 0.18 (0.007) M T L S -M S N S -P S X View D-D G1 0.25 (0.010) M T N S -P S L S -M S R 0.18 (0.007) M T L S -M S N S -P S H C + + 0.18 (0.007) M T L S -M S N S -P S 0.18 (0.007) M T N S -P S L S -M S E G K1 K F 44 (Note 1) 0.18 (0.007) 0.18 (0.007) M M T L S -M S N S -P S T N S -P S L S -M S J G1 0.25 (0.010) M D etail S 0.010 (0.004) T Detail S Seating Plane MILLIMETERS INCHES T L S -M S N S -P S Notes: 1. Due to space limitation, the chip is represented by a general (smaller) case outline drawing rather than showing all 44 leads. 2. Datums L, M, N, and P determine where the top of the lead shoulder exits plastic body at mold parting line 3. DIM G1, true position to be measured at Datum T, Seating Plane 4. DIM R and U do not include mold protusion. Allowable mold protusion is 0.25 (0.010) per side. 5. Dimensioning and tolerancing per Ansi Y14.5M, 1982 6. Controlling dimension: Inch DIM A B C E F G H J K R U V W X Y Z G1 K1 Z1 MIN MAX 17.40 17.65 17.40 17.65 4.20 4.57 2.29 2.79 0.33 0.48 1.27 BSC 0.66 0.81 0.51 0.64 16.51 16.66 16.51 16.66 1.07 1.21 1.07 1.21 1.07 1.42 - 0.50 20 10 0 15.50 16.00 1.02 20 10 0 MIN MAX 0.685 0.695 0.685 0.695 0.165 0.180 0.090 0.110 0.013 0.019 0.050 BSC 0.026 0.032 0.020 0.025 0.650 0.656 0.650 0.656 0.042 0.048 0.042 0.048 0.042 0.056 - 0.020 20 10 0 0.610 0.630 0.040 2 10 0 Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 11 www.semtech.com MECHANICALS FOR THE UR5HC418-FB L 33 34 23 DS B 22 DS A,B,D B 0.20 (0.008) M C A-B S 0.05 (0.002) A-B A L B V 0.20 (0.008) M H A-B S Detail A Detail A 44 1 11 12 D A 0.20 (0.008) M C A-B S 0.05 (0.002) A-B DS Notes 1. Dimensioning and tolerancing per Ansi Y14.5-M, 1982 2. Controlling dimension: Millimeter 3. Datum Plane "H" is located at the bottom of the lead and is coincident with the lead where the lead exits the plastic body at the bottom of the parting line. 4. Datums -A-, -B-, and -D- to be determined at Datum Plane -H-. 5. Dimensions S and V to be determined at seating plane -C-. 6. Dimensions A and B do not include Mold protusion. Allowable protusion is 0.25 (0.010) per side. Dimensions A and B do include mold mismatch and are determined at Datum Plane -H-. 7. Dimension D does not include Danbar protrusion. Allowable Danbar protrusion is 0.08 (0.003) total in excess of the D dimension at Maximum Material Condition. Danbar cannot be located on the lower radius or the foot. MILLIMETERS INCHES F S 0.20 (0.008) M H A-B S DS Base Metal J N M T Datum Plane D 0.20 (0.008) M C A-B S DS R Section B-B DIM A B C D E F G H J K L M N Q R S T U V W X H W X M Detail C K Q Detail C C C Seating Plane E H Datum Plane 0.01 (0.004) G H M MIN MAX 9.90 10.10 9.90 10.10 2.10 2.45 0.30 0.45 2.00 2.10 0.30 0.40 0.80 BSC - 0.25 0.13 0.23 0.65 0.95 8.00 REF 50 10 0 0.13 0.17 00 70 0.13 .30 12.95 13.45 0.13 00 12.95 13.45 0.40 1.6 REF MIN MAX 0.390 0.398 0.390 0.398 0.083 0.096 0.012 0.018 0.079 0.083 0.012 0.016 0.031 BSC - 0.010 0.005 0.009 0.026 0.037 0.315 REF 50 10 0 0.005 0.007 00 70 0.005 0.012 0.510 0.530 0.005 00 0.510 0.530 0.016 0.063 REF Copyright ©1997-2001 Semtech Corporation DOC5-418-DS-109 12 www.semtech.com ELECTRICAL SPECIFICATIONS Absolute Maximum Ratings Ratings Supply Voltage Input Voltage Current Drain per Pin (not including Vss or Vdd) Operating Temperature UR5HC418-XX Storage Temperature Range Thermal Characteristics Characteristic Thermal Resistance Plastic DIP Cerdip PLCC Symbol Vdd Vin I TA Tstg Value -0.3 to +7.0 Vss -0.3 to Vdd +0.3 25 T low to T high -40 to +85 -65 to +150 Unit V V mA °C °C Symbol Tja Value 60 -60 70 Unit °C per W DC Electrical Characteristics (Vdd=5.0 Vdc +/-10%, Vss=0 Vdc, Temperature Characteristic Symbol Min Output Voltage (I load