W77E058A40DL Datasheet, PDF (16/87 Pages) Nuvotem Talema – GENERAL DESCRIPTION

W77E058A
Clock Control
Bit:
7
WD1
6
WD0
Mnemonic: CKCON
5
T2M
4
T1M
3
T0M
2
MD2
1
MD1
Address: 8Eh
0
MD0
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
2¹⁷
2¹⁷ + 512
0
1
2²⁰
2²⁰ + 512
1
0
2²³
2²³ + 512
1
1
2²⁶
2²⁶ + 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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