E202075_HD404889 Datasheet, PDF (108/202 Pages) Renesas Technology Corp – Low-Voltage AS Microcomputers with On-Chip LCD Circuit

HD404889/HD404899/HD404878/HD404868 Series
Timer D Registers: Timer D operation setting and timer D value reading/writing is controlled by the
following registers.
Timer mode register D1 (TMD1: $018)
Timer mode register D2 (TMD2: $019)
Timer write register D (TWDL: $01A, TWDU: $01B)
Timer read register D (TRDL: $01A, TRDU: $01B)
Port mode register 2 (PMR2: $00A)
Module standby register 1 (MSR1: $00D)
• Timer mode register D1 (TMD1: $018):
Timer mode register D1 (TMD1) is a 4-bit write-only register, used to select free-running/reload timer
operation, the input clock, and the prescaler division ratio as shown in figure 56.
Timer mode register D1 (TMD1) is reset to $0 by an MCU reset.
A modification of timer mode register D1 (TMD1) becomes effective after execution of two
instructions following the timer mode register D1 (TMD1) write instruction. The program must provide
for timer D initialization by writing to timer write register D (TWDL, TWDU) to be executed after the
post-modification mode has become effective.
When timer D is set to operate as an input capture timer, an internal clock should be set as the input
clock.
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