SN8P2604A
8-Bit Micro-Controller
8.4.1 OVERVIEW
PWM function is generated by TC1 timer counter and output the PWM signal to PWM1OUT pin (P5.3). The 8-bit
counter counts modulus 256, 64, 32, 16 controlled by ALOAD1, TC1OUT bits. The value of the 8-bit counter (TC1C) is
compared to the contents of the reference register (TC1R). When the reference register value (TC1R) is equal to the
counter value (TC1C), the PWM output goes low. When the counter reaches zero, the PWM output is forced high. The
low-to-high ratio (duty) of the PWM1 output is TC1R/256, 64, 32, 16.
MAX. PWM
ALOAD1 TC1OUT PWM duty range TC1C valid value TC1R valid bits value
Frequency
(Fcpu = 4MHz)
7.8125K
31.25K
Remark
0
0
1
1
0
1
0
1
0/256~255/256
0/64~63/64
0/32~31/32
0/16~15/16
0x00~0xFF
0x00~0x3F
0x00~0x1F
0x00~0x0F
0x00~0xFF
0x00~0x3F
0x00~0x1F
0x00~0x0F
Overflow per 256 count
Overflow per 64 count
Overflow per 32 count
Overflow per 16 count
62.5K
125K
The Output duty of PWM is with different TC1R. Duty range is from 0/256~255/256.
0
1
128
254 255
0
1
128
254 255
……
……
……
……
TC1 Clock
TC1R=00H
TC1R=01H
TC1R=80H
TC1R=FFH
Low
High
Low
High
Low
High
Low
SONiX TECHNOLOGY CO., LTD
Page 84
Version 0.3
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