MC68HC11KW1 Datasheet, PDF (161/238 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

9.1.3.1 TOC1–TOC4 — Timer output compare registers
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
Timer output compare 1 (TOC1) high $0016 (bit 15) (14) (13) (12) (11) (10) (9) (bit 8) 1111 1111
Timer output compare 1 (TOC1) low $0017 (bit 7) (6) (5) (4) (3) (2) (1) (bit 0) 1111 1111
Timer output compare 2 (TOC2) high $0018 (bit 15) (14) (13) (12) (11) (10) (9) (bit 8) 1111 1111
Timer output compare 2 (TOC2) low $0019 (bit 7) (6) (5) (4) (3) (2) (1) (bit 0) 1111 1111
Timer output compare 3 (TOC3) high $001A (bit 15) (14) (13) (12) (11) (10) (9) (bit 8) 1111 1111
Timer output compare 3 (TOC3) low $001B (bit 7) (6) (5) (4) (3) (2) (1) (bit 0) 1111 1111
Timer output compare 4 (TOC4) high $001C (bit 15) (14) (13) (12) (11) (10) (9) (bit 8) 1111 1111
Timer output compare 4 (TOC4) low $001D (bit 7) (6) (5) (4) (3) (2) (1) (bit 0) 1111 1111
All output compare registers are 16-bit read-write. Each is initialized to $FFFF at reset. If an output
compare register is not used for an output compare function, it can be used as a storage location.
A write to the high-order byte of an output compare register pair inhibits the output compare
function for one bus cycle. This inhibition prevents inappropriate subsequent comparisons.
Coherency requires a complete 16-bit read or write. However, if coherency is not needed, byte
accesses can be used.
For output compare functions, write a comparison value to output compare registers TOC1–TOC4
and TI4/O5. When TCNT value matches the comparison value, specified pin actions occur.
9.1.3.2 CFORC — Timer compare force register
9
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
Timer compare force (CFORC) $000B FOC1 FOC2 FOC3 FOC4 FOC5 0
0
0 0000 0000
The CFORC register allows forced early compares. FOC[1:5] correspond to the five output
compares. These bits are set for each output compare that is to be forced. The action taken as a
result of a forced compare is the same as if there were a match between the OCx register and the
free-running counter, except that the corresponding interrupt status flag bits are not set. The
forced channels trigger their programmed pin actions to occur at the next timer count transition
after the write to CFORC.
The CFORC bits should not normally be used on an output compare function that is programmed
to toggle its output on a successful compare, because a normal compare occurring immediately
before or after the force would produce a double toggle. This may be undesirable if it happens
quickly, since the resulting output pulse would be very short.
MC68HC11KW1
TIMING SYSTEM
9-9