Specifications

EPC-3305 Hardware Reference
66
Table A-4. Time/counter functions
I/O Addr Functional group R/W Usage
0040 Timer/counter R/W Counter 0 count
0041 R/W Counter 1 count
0042 R/W Counter 2 count
0043 W Command mode
Table A-5. Keyboard controller
I/O Addr Functional group R/W Usage
0060 Keyboard
controller
R/W
R
Data I/O register
Reset Xbus IRQ12/M and IRQ1
0061 NMI status and control R
W
NMI status
NMI control
0064 Keyboard controller R
W
Status register
Command register
Table A-6. Real-time clock
I/O Addr Functional group R/W Usage
0070 Real-time clock,
NMI
W RTC index register = bits 6–0
NMI enable = bit 7
0071 R/W RTC data register
0seconds
1 seconds alarm
2minutes
3 minutes alarm
4hours
5 hours alarm
6 day of week
7 date of month
8month
9year
A status A
B status B
C status C
D status D
E...3F NVRAM
Table A-7. POST checkpoint
I/O Addr Functional group R/W Usage
0080 POST checkpoint W Phoenix BIOS status information