ADLINK Technology CM1-86DX3, Technical Reference

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A.4 IO Register Maps
A.4.1 CMOS Memory and RTC Registers
The RTC internal registers and RAM are organized as two banks of 128 bytes each, called the
standard and extended banks. The first 14 bytes of the standard bank contain the RTC time and
date information along with four registers A-D, that are used for configuration of the RTC. The
extended bank contains a full 128 bytes of battery backed SRAM. All data movement between
the host CPU and the RTC is done through register mapped standard I/O space.
It is not possible to disable the extended bank.
Registers reg_RTC_IR_type and reg_RTC_TR_type are used for
data movement to and from the standard bank.
Table A-6: RTC IO Registers Alias Locations
Register Original IO location
reg_RTC_IR_type
70h
reg_RTC_TR_type 71h
Table A-7: RTC Indexed Registers
Start End Name
00h 00h Seconds
01h 01h Seconds Alarm
02h 02h Minutes
03h 03h Minutes Alarm
04h 04h Hours
05h 05h Hours Alarm
06h 06h Day of Week
07h 07h Day of Month
08h 08h Month
09h 09h Year
0Ah 0Ah Register A
0Bh 0Bh Register B
0Ch 0Ch Register C
0Dh 0Dh Register D
0Eh 7Fh 114 Bytes of User RAM
09h 09h Year
0Ah 0Ah Register A
0Bh 0Bh Register B
0Ch 0Ch Register C
0Dh 0Dh Register D
0Eh 7Fh 114 Bytes of User RAM