M32C8A Datasheet, PDF (175/372 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M32C/80 Series

M32C/8A Group
15. Timers (Timer A)
Table 15.5 Specifications of Event Counter Mode When Handling Two-Phase Pulse Signals on
Timers A2, A3, and A4
Item
Specification
Count source
Count operation
Two-phase pulse signals applied to pins TAiIN and TAiOUT (i = 2 to 4)
• Count direction (increment or decrement) is set by a two-phase pulse signal.
• Reload/Free-run type can be selected.
Reload function: The contents of the reload register are reloaded into the
counter and the count continues when the timer underflows or overflows.
Free-running function: The counter continues running without reloading when
the timer underflows or overflows.
Number of counting
(FFFFh - n + 1): when incrementing
n + 1: for decrementing
n: setting value of the TAi register, 0000h to FFFFh
Count start condition
The TAiS bit in the TABSR Register is set to 1 (count starts)
Count stop condition
The TAiS bit is set to 0 (count stops)
Interrupt request generation timing When the timer overflows or underflows
TAiIN pin function
Two-phase pulse input
TAiOUT pin function
Two-phase pulse input
Read from timer
A read from the TAi register returns a counter value
Write to timer
Selectable function⁽²⁾
• A write to the TAi register while the count is stopped:
The value is written to both the reload register and the counter.
• A write to the TAi register while counting:
The value is written to the reload register (It is transferred to the counter at the
next reload timing).⁽¹⁾
• Normal processing operation (Timers A2 and A3)
While a high-level (“H”) signal is applied to the TAjOUT pin (j = 2, 3), the timer
increments a counter value at the rising edge of the TAjIN pin or decrements a
counter value at the falling edge.
• Multiply-by-4 processing operation (Timers A3 and A4)
The timer increments the counter value in the following timings:
-at the rising edge of TAkIN while TAkOUT is “H” (k = 3, 4)
-at the falling edge of TAkIN while TAkOUT is “L”
-at the rising edge of TAkOUT while TAkIN is “L”
-at the falling edge of TAkOUT while TAkIN is “H”
The timer decrements the counter in the following timings:
-at the rising edge of TAkIN while TAkOUT is “L”
-at the falling edge of TAkIN while TAkOUT is “H”
-at the rising edge of TAkOUT while TAkIN is “H”
-at the falling edge of TAkOUT while TAkIN is “L”
• Counter reset by a Z-phase pulse signal input (Timer A3)
The counter value is cleared to 0 by a Z-phase pulse signal input
NOTES:
1. Wait for one count source cycle or more to write after the count starts.
2. Any operation can be selected for timer A3. Timer A2 is used only for the normal processing operation. Timer
A4 is used only for the multiply-by-4 operation.
Rev.1.00 Jul 15, 2007 Page 158 of 352
REJ09B0385-0100