hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 370

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

Section 9 Timers
9.7.4
Asynchronous event counter operation modes are shown in table 9.21.
Table 9.21 Asynchronous Event Counter Operation Modes
Operation
Mode
AEGSR
ECCR
ECCSR
ECH
ECL
IRQAEC
Event
counter
PWM
Notes: 1. When an asynchronous external event is input, the counter increments but the counter
9.7.5
1. When reading the values in ECH and ECL, the correct value will not be returned if the event
2. Use a clock with a frequency of up to 16 MHz for input to the AEVH and AEVL pins, and
Rev. 7.00 Mar 10, 2005 page 328 of 652
REJ09B0042-0700
counter increments during the read operation. Therefore, if the counter is being used in the 8-
bit mode, clear bits CUEH and CUEL in ECCSR to 0 before reading ECH or ECL. If the
counter is being used in the 16-bit mode, clear CUEL only to 0 before reading ECH or ECL.
ensure that the high and low widths of the clock are at least half the OSC clock cycle duration.
The duty cycle is immaterial.
2. Operates when asynchronous external events are selected; halted and retained
3. Clock control by IRQAEC operates, but interrupts do not.
4. As the clock is stopped in module standby mode, IRQAEC has no effect.
Asynchronous Event Counter Operation Modes
Application Notes
Reset Active
Reset
Reset
Reset
Reset
Reset
Reset
Reset
overflow H/L flags are not affected.
otherwise.
Functions Functions Retained *
Functions Functions Retained *
Functions Functions Retained *
Functions Functions Functions *
Functions Functions Functions *
Functions Functions Retained *
Functions Functions Retained
Sleep
Watch
1
1
1
3
1
1
*
*
2
2
Subactive
Functions
Functions
Functions
Functions *
Functions *
Functions
Retained
2
2
Subsleep
Functions
Functions
Functions
Functions *
Functions *
Functions
Retained
2
2
Standby
Retained *
Retained *
Retained *
Functions *
Functions *
Retained *
Retained
1
1
1
3
1
1
*
*
2
2
Module
Standby
Retained
Retained
Retained
Halted
Halted
Retained *
Retained
4