EM78M680 Datasheet, PDF (18/53 Pages) ELAN Microelectronics Corp – USB Full Speed Microcontroller

Contents
WDT wake-up during Sleep 2 mode
Wake-up on pin change during Sleep 2 mode
*P: Previous value before reset
0
P
P
P
Status of RST, T and P Being Affected by Events
Event
T
P
Power on
1
1
WDTC instruction
1
1
WDT time-out
0
*P
SLEP instruction
1
0
Wake-Up on pin change during Sleep 2 mode
P
P
*P: Previous value before reset
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.
“0” : Watchdog timer with overflow
“1” : Watchdog timer without overflow
R3 [5~7] Page selection bits. These three bits are used to select the page of the
program memory.
PS2
PS1
PS0
Program Memory Page [Address]
0
0
0
Page 0 [000-3FF]
0
0
1
Page 1 [400-7FF]
0
1
0
Page 2 [800-BFF]
0
1
1
Page 3 [C00-FFF]
1
0
0
Page 4 [1000-13FF]
1
0
1
Page 5 [1400-17FF]
6.2.1.5 R4 (RAM Select Register)
Bit 7
BK1
Bit 6
BK0
Bit 5
Ad5
Bit 4
Ad4
Bit 3
Ad3
Bit 2
Ad2
Bit 1
Ad1
Bit 0
Ad0
R4 (RAM select register) contains the address of the registers. When interrupt
occurs , the MCU will save R4 value automatically.
R4 [0~5] are used to select registers (address: 0x00h~0x3Fh) in indirect
addressing mode.
R4 [6~7] are used to determine which bank is activated among the 8 banks. To
select a register bank, refer to the table below:
R4[7]BK1
0
0
R4[6]BK0
0
1
RAM Bank #
Bank 0
Bank 1
12 •
Product Specification (V1.11) 02.10.2007