
25 PULSE WIDTH MODULATION
S1C38000 TECHNICAL MANUAL
EPSON
239
8 bit Resolution mode:
bits 15–8
Sample 1 Bits [7:0]
This field represents the high byte of a two-sample word in 8-bit mode. This byte will be
presented to the PWM1 FIFO after the SAMPLE0 field. In 16-bit mode, this byte
represents the high byte of a 16-bit sample.
bits 7–0
Sample 0 Bits [7:0]
This field represents the low byte of a two sample word. This byte will be presented to
the PWM1 FIFO before the SAMPLE1 field. When used with single 8-bit samples, data
must be written to this byte.
16 bit Resolution:
bits 15–0
Sample Bits [15:0]
This field represents a single 16-bit sample.
This register is the input to the FIFO. When you write successive sample values to this register, they
are automatically loaded into the FIFO in little-endian format. This register is only used when
PWM1 is configured to 8 bit resolution and to enter single 8-bit samples. See Figure 25-3,
“PWMOUT Waveform,” on page 233 for further information.
bits 7–0
Sample 0 Bits [7:0]
This field represents the single 8-bit sample to be loaded into the FIFO. If PWM1 is
configured to 16-bit resolution, accesses to this register is ignored.
See Figure 25-3, “PWMOUT Waveform,” on page 233 for further information.
16 bit Resolution mode:
bits 15–0
PWM1 Period Bits [15:0]
This controls the PWM0 period. When the counter matches the period, the counter is
reset to start another period. A value of 0 indicates a period of 65536 (16 bit resolution).
8 bit Resolution mode:
bits 7–0
PWM1 Period Bits [7:0]
This controls the PWM0 period. When the counter matches the period, the counter is
reset to start another period. A value of 0 indicates a period of 256. The upper 8 bits are
ignored in 8-bit resolution mode.
PWM1 Pulse Width 8-Bit Access Register
PWM[3Ch]
Write Only
n/a
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
n/a
Sample 0
15
14
13
12
11
10
9876543210
PWM1 Period Register
PWM[40h]
Default = 0000 0000h
Read/Write
n/a
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Period
15
14
13
12
11
10
9876543210