M16C30P_07 Datasheet, PDF (130/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
14. Timers
14.2.2 Event Counter Mode
In event counter mode, the timer counts pulses from an external device or overflows and underflows of other
timers (see Table 14.7). Figure 14.19 shows TBiMR Register in Event Counter Mode.
Table 14.7 Specifications in Event Counter Mode
Item
Count Source
Count Operation
Divide Ratio
Count Start Condition
Count Stop Condition
Interrupt Request
Generation Timing
TBiIN Pin Function
Read from Timer
Write to Timer
Specification
• External signals input to TBiIN pin (i=0 to 2) (effective edge can be selected in
program)
• Timer Bj overflow or underflow (j=i-1, however, j=2 if i=0)
• Down-count
• When the timer underflows, it reloads the reload register contents and
continues counting
1/(n+1) n: set value of TBi register 0000h to FFFFh
Set TBiS bit⁽¹⁾ to “1” (= start counting)
Set TBiS bit to “0” (= stop counting)
Timer underflow
Count source input
Count value can be read by reading TBi register
• When not counting and until the 1st count source is input after counting start
Value written to TBi register is written to both reload register and counter
• When counting (after 1st count source input)
Value written to TBi register is written to only reload register
(Transferred to counter when reloaded next)
NOTES:
1. The TB0S to TB2S bits are assigned to the TABSR register bit 5 to bit 7.
Rev.1.22 Mar 29, 2007 Page 114 of 291
REJ09B0179-0122