D.2.8 TIC[1:3]
— Input Capture Registers 1–3
$YFF90E–$YFF912
The input capture registers are 16-bit read-only registers used to latch the value of
TCNT when a specified transition is detected on the corresponding input capture pin.
They are reset to $FFFF.
D.2.9 TOC[1:4]
— Output Compare Registers 1–4
$YFF914–$YFF91A
The 16-bit read/write output compare registers can be used as output waveform con-
trols 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.
D.2.10 TI4/O5
— Input Capture 4/Output Compare 5 Register
$YFF91C
This register serves either as input capture register 4 or output compare register 5, de-
pending on the state of I4/O5 in PACTL.
D
D.2.11 TCTL1/TCTL2
— Timer Control Registers 1 and 2
15
OM5
14
OL5
13
OM4
12
OL4
11
OM3
10
OL3
9
OM2
8
OL2
7
EDGE4
6
5
EDGE3
4
3
EDGE2
2
$YFF91E
1
EDGE1
0
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
TCTL1 determines output compare mode and output logic level. TCTL2 determines
the type of input capture to be performed.
OM/OL[5:2] — Output Compare Mode Bits and Output Compare Level Bits
Each pair of bits specifies an action to be taken when output comparison is successful.
OM/OL[5:2]
00
01
10
11
Action Taken
Timer Disconnected from Output Logic
Toggle OCx Output Line
Clear OCx Output Line to zero
Set OCx Output Line to one
EDGE[4:1] — Input Capture Edge Control
Each pair of bits configures input sensing logic for the corresponding input capture.
EDGE[4:1]
00
01
10
11
Configuration
Capture Disabled
Capture on Rising Edge Only
Capture on Falling Edge Only
Capture on Any (Rising or Falling) Edge
MOTOROLA
D-8
REGISTER SUMMARY
MC68331
USER’S MANUAL
MOTOROLA [ MOTOROLA, INC ]
