Timers
MOTOROLA
MC68360 USER’S MANUAL
7-21
GM1—Gate Mode for Pin 1
This bit is only valid if the gate function is enabled in TMR1 or TMR2.
0 = Restart gate mode. The TGATE1 pin is used to enable/disable count. A falling
TGATE1 pin enables and restarts the count, and a rising edge of TGATE1 disables
the count.
1 = Normal gate mode. This mode is the same as 0, except the falling edge of TGATE1
does not restart the count value in TCN.
7.5.2.3 TIMER MODE REGISTER (TMR1, TMR2, TMR3, TMR4).
TMR1–TMR4 are identi-
cal 16-bit, memory-mapped, read/write registers. These registers are cleared by reset.
NOTE
The TGCR should be initialized prior to the TMRs, or erratic be-
havior may occur. The only exception is the RST bit in the
TGCR, which may be modified at any time.
PS—Prescaler Value
The prescaler is programmed to divide the clock input by values from 1 to 256. The value
00000000 divides the clock by 1; the value 11111111 divides the clock by 256.
CE—Capture Edge and Enable Interrupt
00 = Disable interrupt on capture event; capture function is disabled.
01 = Capture on rising TINx edge only and enable interrupt on capture event.
10 = Capture on falling TINx edge only and enable interrupt on capture event.
11 = Capture on any TINx edge and enable interrupt on capture event.
OM—Output Mode
0 = Active-low pulse on TOUTx for one timer input clock cycle as defined by the ICLK
bits. Thus, TOUTx may be low for one general system clock period, one general
system clock/16 period, or one TINx pin clock cycle period. TOUTx changes occur
on the rising edge of the system clock.
1 = Toggle the TOUTx pin. TOUTx changes occur on the rising edge of the system
clock.
ORI—Output Reference Interrupt Enable
0 = Disable interrupt for reference reached (does not affect interrupt on capture func-
tion).
1 = Enable interrupt upon reaching the reference value.
FRR—Free Run/Restart
0 = Free run. The timer count continues to increment after the reference value is
reached.
1 = Restart. The timer count is reset immediately after the reference value is reached.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PS
CE
OM
ORI
FRR
ICLK
GE