W77C32_07 Datasheet, PDF (15/78 Pages) Winbond – 8-BIT MICROCONTROLLER

W77C32/W77C032A
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 MD1 MD0 Stretch value
000
0
001
1
010
2
011
3
100
4
101
5
110
6
111
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:
7
P1.7
Mnemonic: P1
6
P1.6
5
P1.5
4
P1.4
3
2
1
P1.3 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 External I/O for Timer/Counter 2
P1.1: T2EX Timer/Counter 2 Capture/Reload Trigger
P1.2: RXD1 Serial Port 1 Receive
P1.3: TXD1 Serial Port 1 Transmit
P1.4: INT2 External Interrupt 2
P1.5: INT3 External Interrupt 3
P1.6: INT4 External Interrupt 4
P1.7: INT5 External Interrupt 5
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Publication Release Date: February 1, 2007
Revision A8