AT89C5131A-S3SUM Atmel, AT89C5131A-S3SUM Datasheet - Page 88

• Manufacturer Part Number: AT89C5131A-S3SUM
• Description: IC 8051 MCU FLASH 32K USB 52PLCC
• Manufacturer: Atmel
• Series: AT89C513xr

Specifications of AT89C5131A-S3SUM

• Core Processor: C52X2
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: LED, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 52-PLCC
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1.25 KB
• Interface Type: 2-Wire, EUART, SPI, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 34
• Number Of Timers: 16 bit
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89STK-05
• Minimum Operating Temperature: - 40 C
• Package: 52PLCC
• Device Core: 8051
• Family Name: 89C
• Maximum Speed: 48 MHz
• For Use With: AT89OCD-01 - USB EMULATOR FOR AT8XC51 MCUAT89STK-10 - KIT EVAL APPL MASS STORAGEAT89STK-05 - KIT STARTER FOR AT89C5131
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

17. Keyboard Interface
17.1
17.2
17.2.1
88
Introduction
Description
AT89C5130A/31A-M
Interrupt
The AT89C5130A/31A-M implements a keyboard interface allowing the connection 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 an alternate function of P1 and allow to exit from idle
and power down modes.
The keyboard interface communicates with the C51 core through 3 special function registers:
KBLS, the Keyboard Level Selection register (Table 17-3), KBE, The Keyboard interrupt Enable
register (Table 17-2), and KBF, the Keyboard Flag register (Table 17-1).
The keyboard inputs are considered as 8 independent interrupt sources sharing the same inter-
rupt vector. An interrupt enable bit (KBD in IE1) allows global enable or disable of the keyboard
interrupt (see Figure 17-1). As detailed in Figure 17-2 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 allow keyboard arrangement from 1 by n to 8 by n matrix and allow usage of P1
inputs for other purpose.
Figure 17-1. Keyboard Interface Block Diagram
Figure 17-2. Keyboard Input Circuitry
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P1:x
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Input Circuitry
Vcc
Internal Pull-up
KBLS.x
0
1
KBF.x
KBD
IE1.0
KBE.x
Keyboard Interface
Interrupt Request
KBDIT
4337K–USB–04/08