W77E516 查看數據表（PDF） - Winbond

零件编号

产品描述 (功能)

生产厂家

W77E516

8-BIT MICROCONTROLLER

Winbond 

Preliminary W77E516

WS: Wait State Signal Enable. Setting this bit enables the WAIT signal on P4.0. The device will

sample the wait state control signal WAIT via P4.0 during MOVX instruction. This bit is

time access protected.

TA

WSCON

CKCON

MOV

MOV

ORL

REG C7H

REG C2H

REG 8EH

TA, #AAH

TA, #55H

WSCON, #10000000B; Set WS bit and stretch value = 0 to enable wait signal.

Power Management Register

Bit:

7

6

5

4

CD1

CD0

SWB

-

3

2

1

-

ALE-OFF

-

0

DME0

Mnemonic: PMR

Address: C4h

CD1, CD0: Clock Divide Control. These bit selects the number of clocks required to generate one

machine cycle. There are three modes including divide by 4, 64 or 1024. Switching

between modes must first go back divide by 4 mode. For instance, to go from 64 to

1024 clocks/machine cycle the device must first go from 64 to 4 clocks/machine cycle,

and then from 4 to 1024 clocks/machine cycle.

CD1,

0

0

1

1

CD0

0

1

0

1

Clocks/machine Cycle

Reserved

4

64

1024

SWB: Switchback Enable. Setting this bit allows an enabled external interrupt or serial port activity

to force the CD1, CD0 to divide by 4 state (0,1). The device will switch modes at the start of

the jump to interrupt service routine while a external interrupt is enabled and actually

recognized by micro controller. While a serial port reception, the switchback occurs at the

start of the instruction following the falling edge of the start bit.

ALE0FF: This bit disables the expression of the ALE signal on the device pin during all on-board

program and data memory accesses. External memory accesses will automatically

enable ALE independent of ALEOFF.

0 = ALE expression is enable; 1 = ALE expression is disable

DME0: This bit determines the on-chip MOVX SRAM to be enabled or disabled. Set this bit to 1 will

enable the on-chip 1KB MOVX SRAM.

- 26 -

Share Link: