HD6475328-CP10 HITACHI [Hitachi Semiconductor], HD6475328-CP10 Datasheet - Page 213

• Manufacturer Part Number: HD6475328-CP10
• Description: original Hitachi CMOS microcomputer unit (MCU)
• Manufacturer: HITACHI [Hitachi Semiconductor]

10.6 Synchronization of Free-Running Timers 1 to 3
10.6.1 Synchronization after a Reset
The three free-running timer channels are synchronized at a reset and remained synchronized
until:
• the clock source is changed;
• FRC contents are rewritten; or
• an FRC is cleared.
After a reset, each free-running counter operates on the ø/4 internal clock source.
10.6.2 Synchronization by Writing to FRCs
When synchronization among free-running timers 1 to 3 is lost, it can be restored by writing to the
free-running counters.
Synchronization on Internal Clock Source: When an internal clock is selected, free-running
timers 1 to 3 can be synchronized by writing data to their free-running counters as indicated in
table 10-4.
Table 10-4 Synchronization by Writing to FRCs
Clock Source
ø/4
ø/8
ø/32
m, n: Arbitrary integers
After writing these data, synchronization can be checked by reading the three free-running
counters at the same interval as the write interval. If the read data have the same relative
differences as the write data, the three free-running timers are synchronized.
Write Interval
4n + 1 (states)
8n + 1 (states)
32n + 1 (states)
Write Data
m
m + n
m + 2n
196
(FRC1)
(FRC2)
(FRC3)