MC68331CEH16 Datasheet, PDF (77/84 Pages) Freescale Semiconductor, Inc – 32-Bit Modular Microcontroller

Freescale Semiconductor, Inc.
PAMOD — Pulse Accumulator Mode
0 = External event counting
1 = Gated time accumulation
PEDGE — Pulse Accumulator Edge Control
The effects of PEDGE and PAMOD are shown in the following table.
PAMOD
0
0
1
1
PEDGE
0
1
0
1
Effect
PAI falling edge increments counter
PAI rising edge increments counter
Zero on PAI inhibits counting
One on PAI inhibits counting
PCLKS — PCLK Pin State (Read Only)
I4/O5 — Input Capture 4/Output Compare 5
0 = Output compare 5 enabled
1 = Input capture 4 enabled
PACLK[1:0] — Pulse Accumulator Clock Select (Gated Mode)
PACLK[1:0]
00
01
10
11
Pulse Accumulator Clock Selected
System Clock Divided by 512
Same Clock Used to Increment TCNT
TOF Flag from TCNT
External Clock, PCLK
PACNT — Pulse Accumulator Counter
8-bit read/write counter used for external event counting or gated time accumulation.
TIC[1:3] — Input Capture Registers 1–3
$YFF90E, $YFF910, $YFF912
The input capture registers are 16-bit read-only registers which are used to latch the value of TCNT
when a specified transition is detected on the corresponding input capture pin. They are reset to $FFFF.
TOC[1:4] — Output Compare Registers 1–4
$YFF914, $YFF916, $YFF918, $YFF91A
The output compare registers are 16-bit read/write registers which can be used as output waveform
controls or as elapsed time indicators. For output compare functions, they are written to a desired match
value and compared against TCNT to control specified pin actions. They are reset to $FFFF.
TI4/O5 — Input Capture 4/Output Compare 5 Register
$YFF91C
This register serves either as input capture register 4 or output compare register 5, depending on the
state of I4/O5 in PACTL.
TCTL1/TCTL2 — Timer Control Registers 1–2
$YFF91E
15
14
13
12
11
10
9
8
OM5 OL5 OM4 OL4 OM3 OL3 OM2 OL2
RESET:
0
0
0
0
0
0
0
0
7
6
EDGE4
0
0
5
4
EDGE3
0
0
3
2
EDGE2
0
0
1
0
EDGE1
0
0
TCTL1 determines output compare mode and output logic level. TCTL2 determines the type of input
capture to be performed.
MC68331TS/D
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