W79E632A Datasheet, PDF (43/79 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E632A/W79L632A
Auto-reload Mode, Counting Up/Down
Timer/Counter 2 will be in auto-reload mode as an up/down counter if CP / RL2 bit in T2CON is cleared
and the DCEN bit in T2MOD is set. In this mode, Timer/Counter 2 is an up/down counter whose direction
is controlled by the T2EX pin. A 1 on this pin cause the counter to count up. An overflow while counting
up will cause the counter to be reloaded with the contents of the capture registers. The next down count
following the case where the contents of Timer/Counter equal the capture registers will load an FFFFh
into Timer/Counter 2. In either event a reload will set the TF2 bit. A reload will also toggle the EXF2 bit.
However, the EXF2 bit can not generate an interrupt while in this mode.
T2M = CKCON.5
osc
1/4
1 ^{C/T = T2CON.1}
0
1/12 ₀
1
T2 = P1.0
TR2 = T2CON.2
Down Counting Reload Value
0FFh 0FFh
TL2 TH2
T2EX = P1.1
RCAP2L RCAP2H
Up Counting Reload Value
DCEN = 1
T2CON.7
Timer 2
TF2
Interrupt
EXF2
T2CON.6
Figure 16. 16-Bit Auto-reload Up/Down Counter
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Publication Release Date: Nov. 11, 2009
Revision A10