W77E58 Просмотр технического описания (PDF) - Winbond

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W77E58

8 BIT MICROCONTROLLER

Winbond 

Preliminary W77E58

CLOCK CONTROL

Bit:

7

WD1

6

WD0

5

T2M

4

T1M

3

T0M

2

MD2

1

MD1

0

MD0

Mnemonic: CKCON

Address: 8Eh

WD1-0: Watchdog timer mode select bits: These bits determine the time-out period for the watchdog

timer. In all four time-out options the reset time-out is 512 clocks more than the interrupt time-

out period.

WD1 WD0 Interrupt time-out Reset time-out

0

0

17

2

17

2 + 512

0

1

20

2

20

2 + 512

1

0

23

2

23

2 + 512

1

1

26

2

26

2 + 512

T2M: Timer 2 clock select: When T2M is set to 1, timer 2 uses a divide by 4 clock, and when set to

0 it uses a divide by 12 clock.

T1M: Timer 1 clock select: When T1M is set to 1, timer 1 uses a divide by 4 clock, and when set to

0 it uses a divide by 12 clock.

T0M: Timer 0 clock select: When T0M is set to 1, timer 0 uses a divide by 4 clock, and when set to

0 it uses a divide by 12 clock.

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

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