K25C81-FN

FlexiCoderTM K25C81 Versatile PC/XC/AT/PS/2 Compatible Keyboard Encoder HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODERTM FAMILY DESCRIPTION The FlexiCoder is a versatile, lowpower keyboard encoder. It offers two bi-directional channels for communicating with a PC/XT/AT/PS2 system, and/or any optional keyboard-compatible devices, such as an 83 or 101/102 standard desktop keyboard, OCR, barcode reader, etc. The K25C81 directly interfaces a PC keyboard port, making custom keyboard to system communications fully transparent. TM FEATURES • Directly interfaces a PC keyboard port • Encodes up to 144 custom keys on an 8 X 18 matrix • Buffers up to 122 keycodes • Interfaces to 83/101/102 standard keyboard or other 8042-compatible device APPLICATIONS • • • • • Custom keyboards/keypads Control panels Automatic teller machines Embedded control systems Public Information Kiosks • • • • • Instrumentation Test and Measurement equipment Point of Sales terminals Industrial Controllers Medical Instruments • Enables custom keypad scan codes to remain unaffected by the Shift States of an external keyboard • Includes jumper-selectable autorepeat for designated keys • Offers two-key inhibit scanning mode On an 8 x 18 matrix, the FlexiCoderTM will scan, debounce and encode up to 144 keys. Scan codes corresponding to single keys of the IBM 101 keyboard, or a combination of these keys when depressed with Shift, Ctrl, and Alt keys, are generated with each key press. Custom keypad input is not effected by the Shift States of an external keyboard. Users can conveniently define key assignments on the matrix as single or repeating actions. All keys must be released between key strokes or scanning is suspended. The encoder can buffer up to 122 keycodes, and control inputs and outputs are provided for interfacing with contact keyboards. The FlexiCoder is ideal for use with either BIOS-compatible chip sets or single-board computers for PC systems requiring a custom keyboard / keypad as an alternate or additional input device. Boards and evaluation kits are immediately obtainable and ready to connect. TM PIN ASSIGNMENTS _RESET _IRQ VX C17 R6 RP KD KC EKC EKD C16 C0 C1 C2 C3 C4 C5 C6 C7 Vss 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 Vcc 39 OSCI 38 OSCO R6 C17 VX NC _IRQ _RESET VCC OSCI OSC0 EKC1 NC 36 R7 35 NC 34 R5 33 R4 32 R3 RP KD KC EKC EKD C16 C0 C1 C2 C3 C4 7 6 1 40 39 1 R7 NC R5 R4 R3 R2 R1 R0 C8 C9 C10 C17 VX _IRQ _RESET NC NC VCC OSCI OSCO EKC1 R7 37 EKC1 DIP 31 R2 30 R1 29 R0 28 C8 27 C9 26 C10 25 C11 24 C12 23 C13 22 C14 21 C15 12 PLCC 34 17 18 23 29 28 R6 RP KD KC EKC EKD C16 C0 C1 C2 C3 QFP NC R5 R4 R3 R2 R1 R0 C8 C9 C10 C11 NC C5 C6 C7 VSS NC C15 C14 C13 C12 C11 FlexiCoderTM is a trademark of Semtech Corp. All other trademarks belong to their respective companies. Copyright Semtech, 1997-2001 DOC5-C81-DS-105 1 www.semtech.com C4 C5 C6 C7 NC VSS 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 mm 1.27 mm 0.8 mm TA = -40°C to +85°C K25C81-XX-P K25C81-XX-FN K25C81-XX-FB FUNCTIONAL DIAGRAM Data Buffer Keyboard Encoder Row Data Inputs 8 R0-R7 EKC1 Interrupt Control Column Select Ouputs 18 C0-C17 KC KD PC Communication Channel Mode Control RP EKC EKD 8042 Emulation (Standard Keyboard) Communication Channel Copyright Semtech, 1997-2001 DOC5-C81-DS-105 2 www.semtech.com FUNCTIONAL DESCRIPTION The FlexiCoderTM consists of six major sections (see functional diagram, previous page). These are the Keyboard Encoder, the Mode Control Unit, the PC Communication Channel, the 8042 Emulation Channel, the Interrupt Control Unit and the Data Buffer. These sections communicate with each other and operate concurrently. The controller continuously scans a keyboard organized as an 8 row by 18 column matrix, for a maximum of 144 keys. Smaller-size keyboards can be connected provided that all unused row pins are connected to Vcc. The microcontroller selects one of the 18 column lines (C0-C17) every 512 µS 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 press 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 Keyboard Communication Channel. PIN DEFINITIONS Mnemonic Vcc Vss OSCI OSCO _RESET _IRQ VX RP DIP 40 20 39 38 1 2 3 6 PLCC 44 22 43 42 1 2 4 7 QFP 38 17 37 36 41 42 43 2 TYPE I I I O I I I I Name and Function Power Supply: +5V Ground Oscilator Input Oscilator Output Reset: apply 0 V to provide orderly start-up. Must be tied to Vcc Tie to Vcc. Rollover Mode Selection: tie to Vcc to select N-Key Rollover. Tie to Ground to select Two-Key Inhibit Mode. Keyboard Clock: connects to PC’s keyboard port Clock Line. Keyboard Data: connects to PC’s keyboard port Data Line. External Keyboard Data: connects to external keyboard Data Line. External Keyboard Clock: connects to external keyboard Clock Line. External Keyboard Clock 2: connects to external keyboard Clock Line and is used to generate an interrupt for every Clock Line transition. This signal must be inverted for PC/XT keyboards. Column Select Outputs: select one of columns. KC KD EKD 8 7 10 9 8 11 4 3 6 I/O I/O I/O EKC 9 10 5 I/O EKC1 37 41 35 I C0-C7 12-19 C8-C15 C16 C17 28-21 11 4 3-17 18 19-21 31-24 12 5 8-15 O 26-18 7 44 O I/O R0-R5 R6 R7 NC 29-34 5 36 35 32-37 6 39 38, 3 18, 23 40 27-32 1 34 16, 33 22, 39 40 I I I - Keyboard type selection: this pin is used both as outputs for column select and as input for standard keyboard-type selection. Row data inputs No Connects: these pins are unused. Note: An underscore before a pin mnemonic denotes an active low signal. Copyright Semtech, 1997-2001 DOC5-C81-DS-105 3 www.semtech.com REPEAT KEYS In custom masks, each key can be defined individually to be either Typematic or Single-Touch Action. In the standard mask, all keys are defined to be Single-Touch Action, except the Arrow Keys. Pin RP controls the repeat action of keys that are defined to be Typematic. Repeat Mode RP FUNCTIONAL DESCRIPTION, (CON’T) Switch Matrix Encoding Each matrix location is programmed to represent either a single key or a combination of keys of the IBM-standard 101/102 keyboard. Scan Code Table Sets The FlexiCoderTM supports two scan code table sets. Scan Code Sets 1 and 2 are the default sets for PC/XT and AT/PS/2 systems respectively. For more information, refer to the IBM Technical Reference Manual. Custom scan code tables, including macros, are also available. Operating modes are defined by the logic level of the relevant mode pins in the Mode Control Unit. SPECIAL HANDLING, (CON’T) No repeat action Repeat action L H Table 1: Typematic Action Control The Typematic rate can be controlled by issuing the appropriate commands from the system. SPECIAL HANDLING Scan Matrix Data Integrity The FlexiCoderTM maintains the integrity of the codes corresponding to the scanned matrix locations, independently of the Shift Status of the external keyboard or the system. For example, if a key has been defined on the matrix to send code corresponding to lower case letter “a”, it will still send the scan code for “a” even if the Shift Key has been pressed or the Caps Lock has been set by the external keyboard. This is accomplished by internally maintaining a set of flags to monitor the Shift Status of the external keyboard and the system. If, for instance, the lower case key “a” is found to be pressed and Caps Lock is set, the codes sent will be as follows: 1. Caps Lock Make Code 2. Caps Lock Break (this will reset the Caps Lock status of the system) 3. “a” Make Code 4. “a” Break Code 5. Lock Make Code 6. Caps Lock Break Code (this will restore the Caps Lock status of the system) External Keyboard Connection If an external keyboard was not connected during power-on and then connected at a later time, the controller will proceed with the normal reset routine in order to initialize the external keyboard properly. Thereafter, the FlexiCoderTM checks for the presence of an external keyboard every 2 seconds. After communication has been established, the controller continues checking for the external keyboard’s presence. Should the external keyboard be removed at a later time, the K25C81 detects the disconnection and will reinitiate the reset sequence upon reconnection. This feature allows the user to connect and disconnect an external keyboard at any time without resetting the system. Copyright Semtech, 1997-2001 DOC5-C81-DS-105 4 www.semtech.com EXT. KBD COMMUNICATION The external keyboard communication port of the FlexiCoderTM fully emulates a standard 8042, available to an 83/101/102 external keyboard or other compatible device. Communication with an external keyboard is accomplished via EKC and EKD, Clock and Data lines respectively. A third pin, EKC1 which connects to the Clock Line, interrupts the controller whenever an external keyboard initiates a communication. When power is first applied, the controller proceeds with the standard reset sequence with the external keyboard. Data and commands coming from the external keyboard are buffered in the controller’s FIFO, along with data from the scanned matrix, and then presented to the system as if originating from a single source. Commands and data from the system, after being acknowledged, are then transmitted to the external keyboard. MODE CONTROL The FlexiCoderTM 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 according to the protocol (PC or AT) selected. In addition, the K25C81 supports 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 value in hex. Command Set/Reset Status Indicators Echo Invalid Command Select Alternate Scan Codes Invalid Command Read ID Set Typematic Rate/Delay Enable Default Disable Set Default Hex Value ED EE EF F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE FF These commands are supported in the AT/PS/2 protocol and can be sent to the keyboard at any time. Mode 1 accepts only the ‘reset’ command. Commands shown in italics do not affect the operation of the K25C81. Nevertheless, they are acknowledged and relayed to the external keyboard, if an external standard keyboard is present. 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* *Scan Code Set 2 Table 3: Keyboard Commands to the System (AT/PS/2 protocol) Set All Keys Typematic Make/Break Make Typematic/Make/Break Set Key Type Typematic Make/Break Make Resend Reset When an external keyboard is connected, commands from the system will also be directed to the external keyboard. Presence or absence of an external keyboard will not affect the normal operation of the FlexiCoderTM. Table 2: Keyboard Commands from the System (AT/PS/2 protocol) Copyright Semtech, 1997-2001 DOC5-C81-DS-105 5 www.semtech.com SUGGESTED INTERFACING FOR K25C81-FN (44-PIN PLCC PACKAGE) VCC U1 1 VCC 2 C1 3 TC54VC4502ECB TELCOM .1uF + JP1 C6 10uF VCC R6 1 2 3 JUPERS SETTINGS JP1 1-2: 2-3 PC/XT PC/AT VCC R1 R2 R3 R4 2x4.7K 2x2K 44 VCC RST NC 38 100K 5 12 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 C17 C16 C15 C14 C13 C12 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0 1 EXTERNAL_KBD_PS2DATA EXTERNAL_KBD_PS2CLOCK 11 10 41 9 8 EKD EKC EKC1 KC KD HOST_PS2DATA HOST_PS2CLOCK C2 C3 C4 C5 4x47pF U2 K25C81-FN PLCC 3 23 VCC 2 4 7 IRQ VX RP ODCO OSCI VSS NC NC C17 C16 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 R7 R6 R5 R4 R3 R2 R1 R0 VCC RP1 NET_15K 43 42 R5 1M Y1 4.00MHz AVX PBRC4.00BR 22 (c)1994-2001 USAR SYSTEMS, Inc. Application Circuit for K25C81-FB .6 Document Number K25C81FB.sch Rev STANDARD KEYMAP FOR K25C81 Rows (R0-R7) 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 0 1 F29 F28 Pg Dn Home ] ( v w o p h i a b . , (comma) S T J K A B 1 2 f3 f4 f14 f13 f1 Backspace Ins Esc Back-quote ! ’(Apostrophe) " * Typematic Keys 2 End PgUp ) x q j c - (dash) U L C 3 f6 f12 Rt Arrow* Up Arrow* @ < n n 3 F36 : * y r k d / V M D 4 f5 f15 Dn Arrow* Lft Arrow* > 4 F34 F27 ^ z s l e % W N E 5 f7 f11 F38 R { ? 5 F35 F30 F22 ; t m f & X O F 6 f8 f16 Space Enter } ~ n n 6 F33 F31 F21 [ u n g # Y P G 7 f9 9 F19 $ \ Tab 7 F37 F32 F25 F20 F23 F18 i 0 Z Q H 8 f2 f10 + = | Del Columns (C0–C17) Upper case A–Z correspond to Shift a–Shift z F21–F30 correspond to Ctrl F1–Ctrl F10 F11–F20 correspond to Shift F1–Shift F10 F31–... correspond to Alt F1–Alt F10 Copyright Semtech, 1997-2001 DOC5-C81-DS-105 6 www.semtech.com 2 3 41 38 2x4.7K RST VCC NC 2x2K 33 SUGGESTED INTERFACING FOR K25C81-FB (44-PIN QFP PACKAGE) OSCI ODCO VSS 37 36 17 7 + VCC 10uF R6 100K R1 R2 R3 R4 C6 VCC 1 2 3 Copyright Semtech, 1997-2001 DOC5-C81-DS-105 1 VCC U1 1 VCC C1 TC54VC4502ECB .1uF JP1 JP1 TELCOM JUPERS SETTING S 1-2: 2-3 PC/ T X PC/A T EXTERNAL_KBD_PS2DATA EKD EKC EKC1 KC KD 5 35 4 3 6 EXTERNAL_KBD_PS2CLOCK HOST_PS2DATA C2 C5 4x47pF NC NC NC NC 40 39 16 22 VCC 42 IRQ VX RP 43 2 R7 R6 R5 R4 R3 R2 R1 R0 34 1 32 31 30 29 28 27 K25C81-FB QFP44 HOST_PS2CLOCK C3 C4 U2 C17 C16 C15 C14 C13 C12 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0 44 7 18 19 20 21 23 24. 25 26 15 14 13 12 11 10 9 8 C17 C16 C15 C14 C13 C12 C11 C10 C9 C8 C7 C6 C5 C4 C3 C2 C1 C0 R7 R6 R5 R4 R3 R2 R1 R0 VCC RP1 NET_15K R5 1M Y1 4.00MHz AVX PBRC4.00BR www.semtech.com (c)1994-2001 USAR SYSTEMS, Inc. Application Circuit for K25C81-FB Document Number K25C81FB.sch Rev .6 MECHANICALS FOR THE K25C81-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 Semtech, 1997-2001 DOC5-C81-DS-105 8 www.semtech.com MECHANICALS FOR THE K25C81-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 Semtech, 1997-2001 DOC5-C81-DS-105 9 www.semtech.com MECHANICALS FOR THE K25C81-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 0 0 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 0 0 70 0.005 0.012 0.510 0.530 0.005 00 0.510 0.530 0.016 0.063 REF Copyright Semtech, 1997-2001 DOC5-C81-DS-105 10 www.semtech.com ELECTRICAL SPECIFICATIONS Absolute Maximum Ratings Ratings Supply Voltage Input Voltage Current Drain per Pin (not including Vss or Vdd) Operating Temperature K25C81 Storage Temperature Range 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 Thermal Characteristics Characteristic Symbol Value Unit Thermal Resistence Tja ° C per W Plastic 60 DIP -60 Plcc 70 DC Electrical Characteristics (Vdd=5.0 Vdc +/-10%, Vss=0 Vdc, Temperature range=T low to T high unless otherwise noted) Characteristic Symbol Min Typ Max Unit Output Voltage (I load