ht82k28a Holtek Semiconductor Inc., ht82k28a Datasheet
ht82k28a
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ht82k28a Summary of contents
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... Supports Japanese, Korean and Portuguese Supports Japanese DOS/V 106-key keyboard Supports code set 1, for PS/2 model 30 keyboard General Description The HT82K28A is a keyboard encoder especially de- signed for IBM PC/AT, IBM PS/2 and all compatible ma- chines. The HT82K28A accepts keyboard inputs and contains a 16-character first-in-first-out buffer in which data is Pin Assignment Rev ...
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... Input High Voltage IH Output Low Voltage (R0~R18 Output Low Voltage (DATA, CLOCK) Internal Pull-high Resistance (C0~C7 Internal Pull-high Resistance (CLOCK, DATA) f System Clock SYS Rev. 1.30 HT82K28A Description Input Voltage..............................V 0. Operating Temperature............................... Test Conditions Min. Typ. Max. 4. ...
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... 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 communi- cation between the keyboard and the system is man- aged through the CLOCK and DATA pins ...
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... EF EE Echo ED set/reset status indicators Rev. 1.30 HT82K28A If a key is pressed and held down while keyboard transmission is inhibited, only the first make code is stored in the buffer overflow as a result of typematic action. Four key types are supported as shown: Key type ...
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... Select alternate scan code F0 Send an ACK to the system Clears both output buffer and the typematic key Accept option byte Rev. 1.30 HT82K28A Set all keys F7, F8, F9, FA FA: Set all keys to typematic/make/break F9: Set all keys to make F8: Set all keys to make/break F7: Set all keys to typematic ...
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... Note: The parity bit is either and the 8 data bits, plus the parity bit, always have an odd number HT82K28A 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 ...
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... Rev. 1.30 HT82K28A Key Number Make/Break Code ...
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... +Left-Shift E0 37 /E0 B7 +Ctrl Break Windows Virtual Key HT82K28A Num Lock / / / / ...
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... Rev. 1.30 HT82K28A Key Number Make/Break Code ...
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... Base Break Windows Virtual Key HT82K28A Num Lock / / / / ...
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... Typematic Typematic Typematic Typematic 56 51 Typematic * Different from code set 2 Rev. 1.30 HT82K28A Key # Make/Break Code Note Default Key State Make/Break Make/Break Make/Break Typematic 62 ...
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... Timing Diagrams Data output Keyboard data input Rev. 1.30 HT82K28A 12 June 27, 2002 ...
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... Application Circuits Rev. 1.30 HT82K28A 13 June 27, 2002 ...
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... K107 Arrow ENTER R-SHF L-SHF L-WIN R-WIN Code Set 2 Make/Break Code Set 3 Make/Break HT82K28A C0 PAUSE SCR LOCK K14 NUM 7 NUM 8 NUM 9 NUM + WAKE UP K130 June 27, 2002 ...
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... Package Information 40-pin DIP (600mil) outline dimensions Symbol Min. A 2045 B 535 C 145 D 125 595 I 635 0 Rev. 1.30 HT82K28A Dimensions in mil Nom. Max. 2065 555 155 145 20 70 100 615 670 15 15 June 27, 2002 ...
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... Holtek¢s products are not authorized for use as critical components in life support devices or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw. Rev. 1.30 HT82K28A 16 June 27, 2002 ...