Download

PDF Abstract Text:

HT82K28A Win98 Keyboard Encoder

Pin Assignment

HT82K28A Win98 Keyboard Encoder
Features
Designed for Windows 95 / 98 / NT Supports 3 Windows 95 Keys Supports Power, Sleep and Wake-up Windows 98 ACPI functions Supports Japanese, Korean and Portuguese Supports Japanese DOS / V 106-key keyboard Supports code set 1, for PS / 2 model 30 keyboard
Supports code set 2, for PC / AT, PS / 2 model 50, 60 keyboards Supports code set 3, for PS / 2 model 80 keyboard RC oscillator Phantom key detection Minimal external components Pin-compatible with Holtek HT6547E-2 40-pin DIP package
General Description
The HT82K28A is a keyboard encoder especially designed for IBM PC / AT, IBM PS / 2 and all compatible machines. The HT82K28A accepts keyboard inputs and contains a 16-character first-in-first-out buffer in which data is stored. An inexpensive RC oscillator can be used for the system clock. The device offers the advantage of simple implementation in high performance and low cost keyboard applications.
Pin Assignment
Rev. 1.10 1 July 9, 2001
HT82K28A
Pin Description
R0~R18 NC SCRL NUM CAP CLOCK DATA
Keyboard matrix scanning output pins No connection LED pin LED pin LED pin
I / O Synchronous clock signal. Used to clock the transmission data I / O Bidirectional data transmission line
Absolute Maximum Ratings
Supply Voltage ..............4.75V to 5.25V Storage Temperature ........-55°C to 125°C Input Voltage.........VSS-0.3V to VDD+0.3V Operating Temperature .........0°C to 70°C
Rev. 1.10
July 9, 2001
HT82K28A
Electrical Characteristics
Rev. 1.10
July 9, 2001
HT82K28A
Functional Description
The HT82K28A basic function is to detect key press and release activity and to transmit the corresponding scan code, as well as make and break codes to the system. The device also accepts commands from the system and responds to the system if necessary. All communication between the keyboard and the system is managed through the CLOCK and DATA pins. The keyboard begins to scan for pressed or released keys and commands from the system after the BAT (Basic Assurance Test) has been run. Working modes Three working modes are supported by the HT82K28A. These are setup by the alternate scan code command F0. The various modes are described as follows. Mode 1 · Supports code set 1 for PS / 2 model 30 keyboards. · Enters mode1 after an F0 Command is issued followed by a 1". · Contains an 11 bit data stream, including one start bit (always zero) eight data bits, one parity bit (odd parity) and one stop bit (always one). · All keys are typematic / make / break as default. · The working mode can be changed again in this mode, by issuing an F0 command followed by an option. See the F0 command for more detail. Mode 2
· Supports code set 2 for PC / AT, PS / 2 model 50,
Mode 3
· Supports code set 3, for PS / 2 model 80 key-
boards.
· Enters mode 3 when an F0 command is issued
followed by a 3".
· Contains an 11 bit data stream, including one
start bit (always zero) eight data bits, one parity bit (odd parity) and one stop bit (always one).
Buffers The buffers support the following functions:
· 16-byte FIFO buffer: stores 16 keystrokes
scan codes.
· Additional keystrokes will be ignored. · Response codes, i.e FA / FE.. do not occupy
buffer positions.
Basic assurance test - BAT The following functions are offered by the Basic Assurance Test:
· Turns on LED status indicators. · Keyboard processor test. · RAM test. · Turns off LED status indicators, i.e. the
LEDs.
· Reports the BAT result to the system.
60 keyboards.
· Enters mode 2 after power on.
The working mode can be changed by an F0 command followed by an option byte 1, 2 or 3. See the F0 command for more details. · Contains an 11 bit data stream, including one start bit (always zero) eight data bits, one parity bit (odd parity) and one stop bit (always one) · All keys are typematic / make / break as default.
Rev. 1.10
July 9, 2001
HT82K28A
Power-on Two important activities take place when power is first applied to the keyboard. The first is the presence of an H / W signal POR (Power-On-Reset) that resets the keyboard processor. The second activity is the running of the self test BAT (Basic Assurance Test) routine.
PC-type / mode / code set The following table describes the relationship between different computer types, the working mode and the code sets. PS / 2 30 PC-AT PS / 2 50 PS / 2 60 PS / 2 80 mode 1 mode 2 mode 2 mode 2 mode 3 code set 1 code set 2 code set 2 code set 2 code set 3
The mode can be changed between mode 2 & 3. Keys
· For code set 1, 2
All keys except the PAUSE key have a make and break code. The PAUSE key has a make code only. The defaults except for PAUSE are make / break / typematic. In mode 1, 2 and 3 the key type may be changed to be one of the following:
Note: "make1" send out only one make code. "Make2" continue sending out make codes until key is released. "X" nothing sent out.
· For code set 3
Rev. 1.10
July 9, 2001
HT82K28A
System command table Command FF - reset FE - resend FD - set key type make FC - set key type make / break FB - set key type typematic FA - set all keys typematic / make / break F9 - set all keys make F8 - set all keys make / break F7 - set all keys typematic F6 - set default F5 - default disabled F4 - enable F3 - set typematic rate / delay F2 - Read ID F1 F0 - select alternate scan codes EF EE - Echo ED - set / reset status indicators The keyboard should respond within 20ms, except when performing the BAT or executing a reset command. Command description
· Default disable - F5
· Enable - F4
· Invalid command
Send an FE to the system No further activities Note: No ACK
Send an EE to the system Continue scanning if the keyboard is enabled Note: This command does not need to feed back the ACK
Rev. 1.10
July 9, 2001
HT82K28A
· Resend - FE
Send the last code to the system Note: No FA response
· Reset - FF
· Select alternate scan code - F0
· Set all keys - F7, F8, F9, FA
· Set typematic rate / delay - F3
· Set default - F6
· Set key type - FB, FC, FD
FB : Set key type - Typematic FC : Set key type - Make / Break
Rev. 1.10
July 9, 2001
HT82K28A
b4~b0 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111
· Default
Typematic rate 30.0 26.7 24.0 21.8 20.0 18.5 17.1 16.0 15.0 13.3 12.0 10.9 10.0 9.2 8.6 8.0
b4~b0 10000 10001 10010 10011 10100 10101 10110 10111 11000 11001 11010 11011 11100 11101 11110 11111
Typematic rate 7.5 6.7 6.0 5.5 5.0 4.6 4.3 4.0 3.7 3.3 3.0 2.7 2.5 2.3 2.1 2.0
· FE: Resend
The KB issues an FE when there is a parity error in transmission.
Data communications
· Data output
· Data input
Commands to the system 00: keyboard detect a error / overrun (set 2, set 3) AB, 83: keyboard ID AA: BAT completion FC: BAT failure EE: Echo FA: Acknowledge FE: Resend FF: Keyboard detects a overrun (set 1)
· FA: Acknowledge
If the KB (Keyboard) receives any valid input except EE (echo) and resend (FE) then send an FA to the system first. If the command is EE, then send an EE back to the system. If the command is FE, then send the last key code to system. If there is an interrupt while sending FA, the KB discards the FA and accepts the command from the system and processes it. · 00 / FF: Key overrun If the keyboard detects an overrun error, the KB sends an overrun error code to the system. mode 1: FF mode 2, 3: 00
Rev. 1.10 8
If the keyboard "data" line is found to be at an inactive level following the 10th bit, a frame error has occurred, and the keyboard continues to count until the "data" line becomes active. The keyboard then makes the "data" line inactive and sends a Resend.
July 9, 2001
HT82K28A
Data stream Mode 1, 2, 3 B1: B2: b3: b4: b5: B6 b7: b8: b9: b10: b11: start bit always 0 data bit 0 data bit 1 data bit 2 data bit 3 data bit 4 data bit 5 data bit 6 data bit 7 parity bit (odd par) stop bit always 1
Note: The parity bit is either 1 or 0, and the 8 data bits, plus the parity bit, always have an odd number of 1 s.
Rev. 1.10
July 9, 2001
HT82K28A
Rev. 1.10
July 9, 2001
HT82K28A
Key code set 1 Base Case Left-Shift Right-Shift Shift+Num E0 B6 E0 52 E0 AA E0 52 E0 52 75 / E0 D2 E0 36 / E0 D2 E0 2A / E0 D2 E0 B6 E0 53 E0 AA E0 53 E0 53 76 / E0 D3 E0 36 / E0 D3 E0 2A / E0 D3 E0 B6 E0 4B E0 AA E0 4B E0 4B 79 / E0 CB E0 36 / E0 CB E0 2A / E0 CB E0 B6 E0 47 E0 AA E0 47 E0 47 80 / E0 C7 E0 36 / E0 C7 E0 2A / E0 C7 E0 B6 E0 4F E0 AA E0 4F E0 4F 81 / E0 CF E0 36 / E0 CF E0 2A / E0 CF E0 B6 E0 48 E0 AA E0 48 E0 48 83 / E0 C8 E0 36 / E0 C8 E0 2A / E0 C8 E0 B6 E0 50 E0 AA E0 50 E0 50 84 / E0 D0 E0 36 / E0 D0 E0 2A / E0 D0 E0 B6 E0 49 E0 AA E0 49 E0 49 85 / E0 C9 E0 36 / E0 C9 E0 2A / E0 C9 E0 B6 E0 51 E0 AA E0 51 E0 51 86 / E0 D1 E0 36 / E0 D1 E0 2A / E0 D1 E0 B6 E0 4D E0 AA E0 4D E0 4D 89 / E0 CD E0 36 / E0 CD E0 2A / E0 CD E0 5B E0 AA E0 5B E0 B6 E0 5B L Win / E0 DB / E0 DB E0 2A / E0 DB E0 36 E0 5C E0 AA E0 5C E0 B6 E0 5C R Win / E0 DC / E0 DC E0 2A / E0 DC E0 36 E0 5D E0 AA E0 5D E0 B6 E0 5D APP / E0 DD / E0 DD E0 2A / E0 DD E0 36 When both shift keys are held down: Both Shift key number 75 E0 AA E0 B6 E0 52 / E0 D2 E0 2A E0 36 Key Number Key Number 95 Base E0 35 / E0 B5 +Left-Shift E0 AA E0 35 / E0 B5 E0 2A Both Shift E0 AA E0 B6 E0 35 / E0 B5 E0 2A E0 36 +Left-Shift E0 37 / E0 B7 Num Lock E0 2A E0 52 / E0 D2 E0 AA E0 2A E0 53 / E0 D3 E0 AA E0 2A E0 4B / E0 CB E0 AA E0 2A E0 47 / E0 C7 E0 AA E0 2A E0 4F E0 CF E0 AA E0 2A E0 48 E0 C8 E0 AA E0 2A E0 50 / E0 D0 E0 AA E0 2A E0 49 / E0 C9 E0 AA E0 2A E0 51 E0 D1 E0 AA E0 2A E0 4D E0 CD E0 AA E0 2A E0 5B / E0 DB E0 AA E0 2A E0 5C / E0 DC E0 AA E0 2A E0 5D / E0 DD E0 AA
+Right-Shift E0 B6 E0 35 / E0 B5 E0 36
when both shift keys are held down: key number 95 Key Number 124 Base E0 2A E0 37 / E0 B7 E0 AA
+Right-Shift 54 / D4
Key Number Base +Ctrl 126 E1 1D 45 E1 9D C5 E0 46 E0 C6 This key is not typematic, all associated scan codes occur on the make code. ACPI Key Power Sleep Wake
Rev. 1.10
Make E0 5E E0 5F E0 63
Break E0 DE E0 DF E0 E3
Windows Virtual Key N / A N / A N / A
July 9, 2001
HT82K28A
Rev. 1.10
July 9, 2001
HT82K28A
Key code set 2 Key Number 75 76 79 80 81 83 84 85 86 89 L Win R Win APP Base Case Shift+Num E0 70 / E0 F0 72 E0 71 / E0 F0 71 E0 6B / E0 F0 6B E0 6C / E0 F0 6C E0 69 / E0 F0 69 E0 75 / E0 F0 75 E0 72 / E0 F0 72 E0 7D / E0 F0 7D E0 7A / E0 F0 7A E0 74 / E0 F0 74 E0 1F / E0 F0 1F E0 27 / E0 F0 27 E0 2F / E0 F0 2F Left-Shift E0 F0 12 E0 70 / E0 F0 70 E0 12 E0 F0 12 E0 70 / E0 F0 71 E0 12 E0 F0 12 E0 70 / E0 F0 6B E0 12 E0 F0 12 E0 70 / E0 F0 6C E0 12 E0 F0 12 E0 70 / E0 F0 69 E0 12 E0 F0 12 E0 70 / E0 F0 75 E0 12 E0 F0 12 E0 70 / E0 F0 72 E0 12 E0 F0 12 E0 70 / E0 F0 7D E0 12 E0 F0 12 E0 70 / E0 F0 7A E0 12 E0 F0 12 E0 70 / E0 F0 74 E0 12 E0 F0 12 1F / E0 F0 1F E0 12 E0 F0 12 27 / E0 F0 27 E0 12 E0 F0 12 2F / E0 F0 2F E0 12 Right-Shift Num Lock
When both shift keys are held down: key number 75 Key Number 95 Base E0 4A / E0 F0 4A
When both shift keys are held down: key number 95 Key Number 124 Base E0 12 E0 7C / E0 F0 7C E0 12
+Left-Shift E0 F0 12 E0 4A / E0 F0 4A E0 12 Both Shift E0 F0 12 E0 F0 59 E0 4A / E0 F0 4A E0 12 E0 59 +Shift / +Ctrl E0 7C / E0 F0 7C
+Alt 84 / F0 84
Key Number Base +Ctrl 126 E1 14 77 E1 F0 14 F0 77 E0 7E E0 F0 7E Note: this key is not typematic, all associated scan codes occur on the make of the key. ACPI key Power Sleep Wake Make E0 37 E0 3F E0 5E Break E0 F0 37 E0 F0 3F E0 F0 5E Windows Virtual Key N / A N / A N / A
Rev. 1.10
July 9, 2001
HT82K28A
Key code set 3 Key # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Make / Break Code 0E / F0 0E 16 / F0 16 1E / F0 1E 26 / F0 26 25 / F0 25 2E / F0 2E 36 / F0 36 3D / F0 3D 3E / F0 3E 46 / F0 46 45 / F0 45 4E / F0 4E 55 / F0 55 5D / F0 5D 66 / F0 66 0D / F0 0D 15 / F0 15 1D / F0 1D 24 / F0 24 2D / F0 2D 2C / F0 2C 35 / F0 35 3C / F0 3C 43 / F0 43 44 / F0 44 4D / F0 4D 54 / F0 54 5B / F0 5B 5C / F0 5C 14 / F0 14 Note Default Key State Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Make / Break Key # 57 58 60 61 62 64 75 76 79 80 81 83 84 85 86 89 90 91 92 93 95 96 97 98 99 100 101 102 103 104 Make / Break Code 59 / F0 59 11 / F0 11 19 / F0 19 29 / F0 29 39 / F0 39 58 / E0 58 67 / F0 67 64 / F0 64 61 / F0 61 6E / F0 6E 65 / F0 65 63 / F0 63 60 / F0 60 6F / F0 60 6D / F0 6D 6A / F0 6A 76 / F0 76 6C / F0 6C 6B / F0 6B 69 / F0 69 77 / F0 77 75 / F0 75 73 / F0 73 72 / F0 72 70 / F0 70 7E / F0 7E 7D / F0 7D 74 / F0 74 7A / F0 7A 71 / F0 71 Note Default Key State Make / Break Make / Break Make / Break Typematic Make Only Make Only Make Only Typematic Typematic Make Only Make Only Typematic Typematic Make Only Make Only Typematic Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only
Rev. 1.10
July 9, 2001
HT82K28A
Key # 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 Make / Break Code 1C / F0 1C 1B / F0 1B 23 / F0 23 2B / F0 2B 34 / F0 34 33 / F0 33 3B / F0 3B 42 / F0 42 4B / F0 4B 4C / F0 4C 52 / F0 52 5D / F0 5D 5A / F0 5A 12 / F0 12 13 / F0 13 1A / F0 1A 22 / F0 22 21 / F0 21 2A / F0 2A 32 / F0 32 31 / F0 31 3A / F0 3A 41 / F0 41 49 / F0 49 4A / F0 4A 51 / F0 51 Note Default Key State Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Make / Break Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Typematic Key # 105 106 107 108 110 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 131 132 133 L Win R Win APP Make / Break Code 84 / F0 84 7C / F0 7C 7B / F0 7B 79 / F0 79 08 / F0 08 07 / F0 07 0F / F0 0F 17 / F0 17 1F / F0 1F 27 / F0 27 2F / F0 2F 37 / F0 / 37 3F / F0 3F 47 / F0 47 4F / F0 4F 56 / F0 56 5E / F0 5E 57 / F0 57 5F / F0 5F 62 / F0 62 85 / F0 85 86 / F0 86 87 / F0 87 8B / F0 8B 8C / F0 8C 8D / F0 8D Note Default Key State Make Only Typematic Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make Only Make / Break Make / Break Make / Break
Different from code set 2
Rev. 1.10
July 9, 2001
HT82K28A
Timing Diagrams
Data output
Keyboard data input
Rev. 1.10
July 9, 2001
HT82K28A
Application Circuits
Rev. 1.10
July 9, 2001
HT82K28A
Rev. 1.10
July 9, 2001
HT82K28A
The above key code is according to the Microsoft specification except for the following keys. Key No 14 94 109 129 130 Code Set 1 Make / Break 7D 7C 78 F1 F0 FD FC F8 Code Set 2 Make / Break 6A 68 63 F1 F2 F0 6A F0 68 F0 63 Code Set 3 Make / Break 5D 68 78 F1 F2 F0 5D F0 68 F0 78
Rev. 1.10
July 9, 2001
HT82K28A
Rev. 1.10
July 9, 2001