AT89C5130A-M Atmel Corporation, AT89C5130A-M Datasheet - Page 80

• Manufacturer Part Number: AT89C5130A-M
• Manufacturer: Atmel Corporation

Specifications of AT89C5130A-M

• Flash (kbytes): 16 Kbytes
• Max. Operating Frequency: 48 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Sram (kbytes): 1.25
• Eeprom (bytes): 1024
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART/USB
• Watchdog: Yes

16.2
80
Registers
AT89C5130A/31A-M
Each interrupt source can also be individually programmed to one out of four priority levels by
setting or clearing a bit in the Interrupt Priority register (Table 16-3.) and in the Interrupt Priority
High register
each combination.
The PCA interrupt vector is located at address 0033H, the SPI interrupt vector is located at
address 004BH and Keyboard interrupt vector is located at address 003BH. All other vectors
addresses are the same as standard C52 devices.
Table 16-1.
A low-priority interrupt can be interrupted by a high priority interrupt, but not by another low-prior-
ity interrupt. A high-priority interrupt can’t be interrupted by any other interrupt source.
If two interrupt requests of different priority levels are received simultaneously, the request of
higher priority level is serviced. If interrupt requests of the same priority level are received simul-
taneously, an internal polling sequence determines which request is serviced. Thus within each
priority level there is a second priority structure determined by the polling sequence.
Table 16-2.
IEN0 - Interrupt Enable Register (A8h)
EA
7
(Table
IPH.x
Priority Level Bit Values
IEN0 Register
0
0
1
1
EC
6
16-4). Table 16-1. shows the bit values and priority levels associated with
ET2
5
ES
4
IPL.x
0
1
0
1
ET1
3
EX1
2
Interrupt Level Priority
3 (Highest)
0 (Lowest)
ET0
1
1
2
4337K–USB–04/08
EX0
0