mc68hc912bc32 Freescale Semiconductor, Inc, mc68hc912bc32 Datasheet - Page 178

• Manufacturer Part Number: mc68hc912bc32
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Enhanced Capture Timer (ECT) Module
13.4.13 Pulse Accumulators Count Registers
Read: Anytime
Write: Anytime
The two 8-bit pulse accumulators, PAC3 and PAC2, are cascaded to form the PACA 16-bit pulse
accumulator. When PACA in enabled (PAEN = 1 in PACTL, $A0) the PACN3 and PACN2 registers’
contents are, respectively, the high and low bytes of the PACA.
When PACN3 overflows from $FF to $00, the interrupt flag PAOVF in PAFLG ($A1) is set. Full count
register access should take place in one clock cycle. A separate read/write for high byte and low byte will
give a different result than accessing them as a word.
Read: Anytime
Write: Anytime
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Address: $00A2
Address: $00A3
Address: $00A4
Address: $00A5
Reset:
Reset:
Reset:
Reset:
Read:
Read:
Read:
Read:
Write:
Write:
Write:
Write:
Figure 13-31. Pulse Accumulator Count Register 3 (PACN3)
Figure 13-32. Pulse Accumulator Count Register 2 (PACN2)
Figure 13-33. Pulse Accumulator Count Register 1 (PACN1)
Figure 13-34. Pulse Accumulator Count Register 0 (PACN0)
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
Bit 7
0
0
0
0
Bit 6
Bit 6
Bit 6
Bit 6
6
0
6
0
6
0
6
0
M68HC12B Family Data Sheet, Rev. 9.1
Bit 5
Bit 5
Bit 5
Bit 5
5
0
5
0
5
0
5
0
Bit 4
Bit 4
Bit 4
Bit 4
4
0
4
0
4
0
4
0
Bit 3
Bit 3
Bit 3
Bit 3
3
0
3
0
3
0
3
0
Bit 2
Bit 2
Bit 2
Bit 2
2
0
2
0
2
0
2
0
Bit 1
Bit 1
Bit 1
Bit 1
1
0
1
0
1
0
1
0
Freescale Semiconductor
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
Bit 0
0
0
0
0