Hardware manual

Rev. 3.0, 09/98, page 181 of 361
9.1.3 Input and Output Pins
Table 9.1 lists the output pins of the PWM timer module. There are no input pins.
Table 9.1 Output Pins of PWM Timer Module
Name Abbreviation I/O Function
PWM0 output PW0 Output Pulse output from PWM timer channel 0.
PWM1 output PW1 Output Pulse output from PWM timer channel 1.
9.1.4 Register Configuration
The PWM timer module has three registers for each channel as listed in table 9.2.
Table 9.2 PWM Timer Registers
Address
Name Abbreviation R/W Initial Value PWM0 PWM1
Timer control register TCR R/W H'38 H'FFA0 H'FFA4
Duty register DTR R/W H'FF H'FFA1 H'FFA5
Timer counter TCNT R/W H'00 H'FFA2 H'FFA6
9.2 Register Descriptions
9.2.1 Timer Counter (TCNT)H'FFA2 (PWM0), H'FFA6 (PWM1)
Bit:76543210
Initial value:00000000
Read/Write: R/W R/W R/W R/W R/W R/W R/W R/W
The PWM timer counters (TCNT) are 8-bit up-counters. When the output enable bit (OE) in the
timer control register (TCR) is set to “1,” the timer counter starts counting pulses of an internal
clock source selected by clock select bits 2 to 0 (CKS2 to CKS0). After counting from H'00 to
H'F9, the timer counter repeats from H'00.
The PWM timer counters are initialized to H'00 at a reset and in the standby modes, and when the
OE bit is cleared to “0.”