w77e58 Winbond Electronics Corp America, w77e58 Datasheet - Page 57

• Manufacturer Part Number: w77e58
• Description: 8 Bit Microcontroller
• Manufacturer: Winbond Electronics Corp America

CAPTURE MODE
The capture mode is enabled by setting the CP RL
mode, Timer/Counter 2 serves as a 16 bit up counter. When the counter rolls over from FFFFh to
0000h, the TF2 bit is set, which will generate an interrupt request. If the EXEN2 bit is set, then a
negative transition of T2EX pin will cause the value in the TL2 and TH2 register to be captured by the
RCAP2L and RCAP2H registers. This action also causes the EXF2 bit in T2CON to be set, which will
also generate an interrupt. Setting the T2CR bit (T2MOD.3), the W77E58 allows hardware to reset
timer 2 automatically after the value of TL2 and TH2 have been captured.
div. by 4
div. by 64
div. by 1024 osc/256
div. by 4
div. by 64
div. by 1024 osc/256
Mode
Mode
Clock Source
TR0 = TCON.4
EXEN2 = T2CON.3
Clock Source
TR1 = TCON.6
GATE = TMOD.3
TR2 = T2CON.2
INT0 = P3.2
T2EX = P1.1
T0 = P3.4
T2 = P1.0
osc/1
osc/16
input
osc/1
osc/16
input
1/12
1/4
1/12
1/4
T0M = CKCON.3
0
T2M = CKCON.5
1
1
0
1
C/T = TMOD.2
0
Figure 13. Timer/Counter 0 Mode 3
C/T2 = T2CON.1
Figure 14. 16-Bit Capture Mode
0
1
- 57 -
/
2 bit in the T2CON register to a 1. In the capture
0
0
RCAP2L
TL2
TH0
TL0
RCAP2H
TH2
Preliminary W77E58
Publication Release Date: March 1999
7
7
T2CON.7
T2CON.6
EXF2
TF2
TF1
TF0
Interrupt
Interrupt
Interrupt
Timer 2
Revision A1