Chapter 11 Enhanced Capture Timer (S12MC9S12XDP51216B8CV2)
MC9S12XDP512 Data Sheet, Rev. 2.11
Freescale Semiconductor 523
11.3.2.9 Timer Control Register 3/Timer Control Register 4 (TCTL3/TCTL4)
Read or write: Anytime
All bits reset to zero.
Module Base + 0x000A
76543210
REDG7B EDG7A EDG6B EDG6A EDG5B EDG5A EDG4B EDG4A
W
Reset 00000000

Figure 11-13. Timer Control Register 3 (TCTL3)

Module Base + 0x000B
76543210
REDG3B EDG3A EDG2B EDG2A EDG1B EDG1A EDG0B EDG0A
W
Reset 00000000

Figure 11-14. Timer Control Register 4 (TCTL4)

Table 11-11. TCTL3/TCTL4 Field Descriptions

Field Description
EDG[7:0]B
7, 5, 3, 1
Input Capture Edge Control — These eight pairs of control bits configure the input capture edge detector
circuits for each input capture channel. The four pairs of control bits in TCTL4 also configure the input capture
edge control for the four 8-bit pulse accumulators PAC0–PAC3.EDG0B and EDG0A in TCTL4 also determine the
active edge for the 16-bit pulse accumulator PACB. See Table 11-12.
EDG[7:0]A
6, 4, 2, 0

Table 11-12. Edge Detector Circuit Configuration

EDGxB EDGxA Configuration
0 0 Capture disabled
0 1 Capture on rising edges only
1 0 Capture on falling edges only
1 1 Capture on any edge (rising or falling)