7721 Datasheet, PDF (138/577 Pages) List of Unclassifed Manufacturers – H Bridge Power Module

TIMER A
8.4 Event counter mode
Table 8.4.2 Specifications of event counter mode (when using two-phase pulse signal processing function)
Item
Specifications
Count source
Count operation
External signal (two-phase pulse) input to the TAjIN or TAjOUT pin
q Countup or countdown can be switched by external signal (two-
phase pulse).
q When a counter overflow or underflow occurs, reload register’s contents
Division ratio
are reloaded, and counting continues.
q For countdown
1
(n + 1) n : Timer Aj register’s set value
q For countup
1
(FFFF16 – n + 1)
Count start condition
When the count start bit is set to “1.”
Count stop condition
When the count start bit is cleared to “0.”
Interrupt request occurrence timing When a counter overflow or underflow occurs.
TAjIN, TAjOUT pin function
Two-phase pulse input
Read from timer Aj register
Write to timer Aj register
Counter value can be read out.
q While counting is stopped
When a value is written to the timer Aj register, it is written to both
of the reload register and counter.
q While counting is in progress
When a value is written to the timer Aj register, it is written only to
the reload register. (Transferred to the counter at the next reload
time.)
7721 Group User’s Manual
8–19