Rabbit 3000, User Manual

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User’s Manual 85
Table 7-5. Real-Time Clock RTCxR Data Registers
Real-Time Clock x Holding Register (RTC0R) R/W (Address = 0x02)
(RTC1R) (Address = 0x03)
(RTC2R) (Address = 0x04)
(RTC3R) (Address = 0x05)
(RTC4R) (Address = 0x06)
(RTC5R) (Address = 0x07)
Bit(s) Value Description
7:0 Read The current value of the 48-bit RTC holding register is returned.
Write
Writing to the RTC0R transfers the current count of the RTC to six holding
registers while the RTC continues counting.
Table 7-6. Real-Time Clock Control Register (RTCCR adr = 01h)
Bit(s) Value Description
7:0
00h
No effect on the RTC counter, disable the byte increment function,
or cancel the RTC reset command (except code 80h)
40h
Arm RTC for a reset with code 80h or reset and byte increment
function with code 0c0h.
80h
Resets all six bytes of the RTC counter to 00h if proceeded by arm
command 40h.
c0h
Resets all six bytes of the RTC counter to 00h and enters byte
increment mode—precede this command with 40h arm command.
7:6 01
This bit combination must be used with every byte increment write
to increment clock(s) register corresponding to bit(s) set to "1".
Example: 01001101 increments registers: 0, 2,3. The byte
increment mode must be enabled. Storing 00h cancels the byte
increment mode.
5:0
0 No effect on the RTC counter.
1 Increment the corresponding byte of the RTC counter.