EM78P809N
8-Bit Microcontroller
General Purpose Registers
Address Name
Reset Type
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Bit Name
-
-
-
-
-
-
-
-
0x10
~
R10
~
Power-On
U
P
P
U
P
P
U
P
P
U
P
P
U
P
P
U
P
P
U
P
P
U
P
P
/RESET and WDT time out
Wake-Up from SLEEP, IDLE mode
0x3F
R3F
X: Not used. U: Unknown or don’t care. P: Previous value before reset. t: Check Table 7
(*) 0: Wake-Up from SLEEP P: Wake-Up from IDLE
4.14.4
The Status of RST, T, and P of STATUS Register
The values of T and P are used to verify the event that triggered the processor to wake
up. Table 7 shows the events that may affect the status of T and P.
Table 7. The Values of RST, T and P after RESET
Reset Type
T
P
Power on
1
*P
*P
*P
0
1
/RESET during Operation mode
/RESET wake-up during SLEEP mode
/RESET wake-up during IDLE mode
WDT during Operation mode
*P
*P
*P
*P
*P
*P
WDT wake-up during SLEEP mode
WDT wake-up during IDLE mode
0
0
*P: Previous status before reset
Table 8 The Events that may Affect the T and P Status
Event
T
P
Power on
1
1
1
1
WDTC instruction
WDT time-out
0
*P
0
SLEP instruction
Wake-Up during SLEEP mode
1
*P
*P
*P: Previous value before reset
Product Specification (V1.0) 07.26.2005
• 53
(This specification is subject to change without further notice)
ELAN [ ELAN MICROELECTRONICS CORP ]
