W79E225A Datasheet, PDF (39/200 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E225A/227A Data Sheet
PORT 4 CHIP-SELECT POLARITY
Bit:
7
6
5
4
3
2
1
0
P43INV P42INV P41INV P40INV -
PWDNH RMWFP PUP0
Mnemonic: P4CSIN
Address: A2h
BIT NAME
7-4 P4xINV
3-
2 PWDNH
1 RMWFP
0 PUP0
FUNCTION
The Active Polarity of P4.x when it is set as a chip-select strobe output. High =
Active High. Low = Active Low. Note: x = 3,2,1,0.
Reserved.
Set PWDNH to logic 1 then ALE and PSEN will keep high state, clear this bit to
logic 0 then ALE and PSEN will output low during power down mode.
Control Read Path of Instruction “Read-Modify-Write”. When this bit is set, the
read path of executing “read-modify-write” instruction is from port pin otherwise
from SFR.
Enable Port 0 weak pull up.
CAPTURE CONTROL 0 REGISTER
Bit:
7
6
5
CCT2.1 CCT2.0 CCT1.1
4
CCT1.0
3
CCT0.1
2
CCT0.0
1
CCLD1
0
CCLD0
Mnemonic: CAPCON0
BIT NAME
FUNCTION
Address: A3h
Capture 2 edge select.
CCT2.1 CCT2.0
Description
0
7-6 CCT2.1-0
0
0 Rising edge trigger
1 Falling edge trigger
1
0 Rising and falling edge trigger
1
1 Reserved.
Capture 1 edge select.
CCT1.1 CCT1.0
Description
0
5-4 CCT1.1-0
0
0 Rising edge trigger
1 Falling edge trigger
1
0 Rising and falling edge trigger
1
1 Reserved.
Capture 0 edge select.
CCT0.1 CCT0.0
Description
0
3-2 CCT0.1-0
0
0 Rising edge trigger
1 Falling edge trigger
1
0 Rising and falling edge trigger
1
1 Reserved.
- 39 -
Publication Release Date: December 14, 2007
Revision A2.0