AT83C5122_08 ATMEL [ATMEL Corporation], AT83C5122_08 Datasheet - Page 153
AT83C5122_08
Manufacturer Part Number
AT83C5122_08
Description
C51 Microcontroller with USB and Smart Card Reader Interfaces
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT83C5122_08.pdf
(208 pages)
- Current page: 153 of 208
- Download datasheet (3Mb)
Keyboard Interface
Introduction
Description
Interrupt
4202F–SCR–07/2008
Only for AT8xC5122.
The AT83R5122, AT8xC5122/23 implements a keyboard interface allowing the connec-
tion of a 8 x n matrix keyboard. It is based on 8 inputs with programmable interrupt
capability on both high or low level. These inputs are available as alternate function of
P5 and allow to exit from idle and power-down modes.
The keyboard interfaces with the C51 core through 3 special function registers: KBLS,
the Keyboard Level Selection register (Table 96 on page 156), KBE, The Keyboard
interrupt Enable register (Table 95 on page 155), and KBF, the Keyboard Flag register
(Table ).
The keyboard inputs are considered as 8 independent interrupt sources sharing the
same interrupt vector. An interrupt enable bit ( KBD in IE1) allows global enable or dis-
able of the keyboard interrupt (see Figure 97). As detailed in Figure 98 each keyboard
input has the capability to detect a programmable level according to KBLS.x bit value.
Level detection is then reported in interrupt flags KBF.x that can be masked by software
using KBE.x bits.
This structure allows keyboard arrangement from 1 by n to 8 by n matrix and allows
usage of P5 inputs for other purpose.
The KBF.x flags are set by hardware when an active level is on input P5.x. They are
automatically reset after any read access on KBF. If the content of KBF must be ana-
lyzed, the first read instruction must transfer KBF contend to another location. The KBF
register cannot be written by software.
Figure 97. Keyboard Interface Block Diagram
Figure 98. Keyboard Input Circuitry
P5.x
P5.0
P5.1
P5.2
P5.3
P5.4
P5.5
P5.6
P5.7
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
KBLS.x
0
1
AT83R5122, AT8xC5122/23
KBF.x
KBE.x
IEN1.0
EKB
Keyboard Interface
Interrupt Request
KBDIT
153
Related parts for AT83C5122_08
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
Atmel CryptoMemory, 16Kbit
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontrollers
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 16/32/64/128K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 16/32/64K Bytes In-System Programmable Programmable
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet: