W77C58 Datasheet, PDF (13/71 Pages) Winbond – 8 BIT MICROCONTROLLER

Preliminary W77C58
MD2-0: Stretch MOVX select bits: These three bits are used to select the stretch value for the MOVX
instruction. Using a variable MOVX length enables the user to access slower external memory
devices or peripherals without the need for external circuits. The RD or WR strobe will be
stretched by the selected interval. When accessing the on-chip SRAM, the MOVX instruction
is always in 2 machine cycles regardless of the stretch setting. By default, the stretch has
value of 1. If the user needs faster accessing, then a stretch value of 0 should be selected.
MD2
0
0
0
0
1
1
1
1
MD1
0
0
1
1
0
0
1
1
MD0
0
1
0
1
0
1
0
1
Stretch value
0
1
2
3
4
5
6
7
MOVX duration
2 machine cycles
3 machine cycles (Default)
4 machine cycles
5 machine cycles
6 machine cycles
7 machine cycles
8 machine cycles
9 machine cycles
Port 1
Bit:
Mnemonic: P1
7
P1.7
6
P1.6
5
P1.5
4
P1.4
3
P1.3
2
1
P1.2 P1.1
Address: 90h
0
P1.0
P1.7-0: General purpose I/O port. Most instructions will read the port pins in case of a port read
access, however in case of read-modify-write instructions, the port latch is read. Some pins
also have alternate input or output functions. This alternate functions are described below:
P1.0 : T2
P1.1 : T2EX
P1.2 : RXD1
P1.3 : TXD1
P1.4 : INT2
P1.5 : INT3
P1.6 : INT4
P1.7 : INT5
External I/O for Timer/Counter 2
Timer/Counter 2 Capture/Reload Trigger
Serial Port 1 Receive
Serial Port 1 Transmit
External Interrupt 2
External Interrupt 3
External Interrupt 4
External Interrupt 5
External Interrupt Flag
Bit:
7
6
5
4
3
2
1
0
IE5 IE4 IE3 IE2 _XT/RG RGMD RGSL 0
Mnemonic: EXIF
Address: 91h
IE5: External Interrupt 5 flag. Set by hardware when a falling edge is detected on INT5 .
IE4: External Interrupt 4 flag. Set by hardware when a rising edge is detected on INT4.
IE3: External Interrupt 3 flag. Set by hardware when a falling edge is detected on INT5 .
IE2: External Interrupt 2 flag. Set by hardware when a rising edge is detected on INT2.
- 13 -
Publication Release Date: September 1999
Revision A1