EM78M612
Universal Serial Bus Microcontroller Series
R3 (Status Register) Default Value:(0B_0001_1000)
7
6
-
5
PS0
4
T
3
P
2
Z
1
DC
0
C
SPRBS
R3 [0] Carry flag.
R3 [1] Auxiliary carry flag.
R3 [2] Zero flag. It will be set to 1 when the result of an arithmetic or logic operation is
zero.
R3 [3] Power down flag. It will be set to 1 during Power-on phase or by “WDTC” command
and cleared when the MCU enters into Power down mode. It remains in its previous
state after WatchDog Reset.
1: Power-on.
0: Power down
R3 [4] Time-out flag. It will be set to 1 during Power-on phase or by “WDTC” command. It
is reset to 0 by WDT time-out.
1: WatchDog timer without overflow.
0: WatchDog timer with overflow.
The various states of Power down flag and Time-out flag at different conditions are shown
below:
T
P
Condition
1
1
0
1
1
1
1
Power-on reset
WDTC instruction
*P WDT time-out
0
0
Power down mode
Wakeup caused by port change during Power down mode
*P: Previous status before WDT reset
R3 [5] Page selection bit. This bit is used to select a page of program memory (refer to R2,
Program Counter).
PS0
0
Program Memory Page [Address]
Page 0 [0000-03FF]
1
Page 1 [0400-07FF]
R3 [6] General purpose registers.
R3 [7] Special purpose registers bank selector.
1: R8S ~ RFS; IOC8S ~ IOCFS
0: R5 ~ RF; IOC5 ~ IOCF
This specification may change without further notice.
2004/4/28 V1.1
11
ELAN [ ELAN MICROELECTRONICS CORP ]
