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

0x10

 

R10

 

Bit Name

 

-

 

-

 

-

 

-

 

-

 

-

 

-

 

-

 

Power-On

 

U

 

U

 

U

 

U

 

U

 

U

 

U

 

U

~

 

~

 

 

 

 

 

 

 

 

 

 

 

/RESET and WDT time out

 

P

 

P

 

P

 

P

 

P

 

P

 

P

 

P

0x3F

 

R3F

 

 

 

 

 

 

 

 

 

 

 

Wake-Up from SLEEP, IDLE mode

 

P

 

P

 

P

 

P

 

P

 

P

 

P

 

P

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

4.14.4The 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

1

 

 

 

/RESET during Operation mode

*P

*P

 

 

 

/RESET wake-up during SLEEP mode

*P

*P

 

 

 

/RESET wake-up during IDLE mode

*P

*P

 

 

 

WDT during Operation mode

0

*P

 

 

 

WDT wake-up during SLEEP mode

0

*P

 

 

 

WDT wake-up during IDLE mode

0

*P

 

 

 

*P: Previous status before reset

Table 8 The Events that may Affect the T and P Status

Event

 

T

 

P

 

 

 

 

 

 

 

Power on

 

1

 

1

 

 

 

 

 

 

 

WDTC instruction

 

1

 

1

 

 

 

 

 

 

WDT time-out

 

0

 

*P

 

 

 

 

 

 

SLEP instruction

 

1

 

0

 

 

 

 

 

 

Wake-Up during SLEEP mode

 

*P

 

*P

 

 

 

 

 

 

*P: Previous value before reset

Product Specification (V1.0) 07.26.2005

53

(This specification is subject to change without further notice)

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IBM EM78P809N Status of RST, T, and P of Status Register, Bit Microcontroller General Purpose Registers, Reset Type, Event