hd66100 Renesas Electronics Corporation., hd66100 Datasheet - Page 329

• Manufacturer Part Number: hd66100
• Description: H8/3867 Series
• Manufacturer: Renesas Electronics Corporation.

11.3
11.3.1
When using the 14-bit PWM, set the registers in the following sequence.
1. Set bit PWM in port mode register 3 (PMR3) to 1 so that pin P3
2. Set bits PWCR1 and PWCR0 in the PWM control register (PWCR) to select a conversion
3. Set the output waveform data in PWM data registers U and L (PWDRU/L). Be sure to write in
where tø is the PWM input clock period: 2/ø (PWCR = H'0), 4/ø (PWCR = H'1), 8/ø (PWCR =
H'2), or 16/ø (PWCR = H'3).
Example: Settings in order to obtain a conversion period of 32,768 µs:
314
output.
period of 131,072/ø (PWCR1 = 1, PWCR0 = 1), 65,536/ø (PWCR1 = 1, PWCR0 = 0),
32,768/ø (PWCR1 = 0, PWCR0 = 1), or 16,384/ø (PWCR1 = 0, PWCR0 = 0).
the correct sequence, first PWDRL then PWDRU. When data is written to PWDRU, the data
in these registers will be latched in the PWM waveform generator, updating the PWM
waveform generation in synchronization with internal signals.
One conversion period consists of 64 pulses, as shown in figure 11.2. The total of the high-
level pulse widths during this period (T
This relation can be represented as follows.
T
H
Operation
Operation
= (data value in PWDRU and PWDRL + 64)
When PWCR1 = 0 and PWCR0 = 0, the conversion period is 16,384/ø, so ø must be
0.5 MHz. In this case, tfn = 512 µs, with 1/ø (resolution) = 2.0 µs.
When PWCR1 = 0 and PWCR0 = 1, the conversion period is 32,768/ø, so ø must be 1
MHz. In this case, tfn = 512 µs, with 2/ø (resolution) = 2.0 µs.
When PWCR1 = 1 and PWCR0 = 0, the conversion period is 65,536/ø , so ø must be 2
MHz. In this case, tfn = 512 µs, with 4/ø (resolution) = 2.0 µs.
Accordingly, for a conversion period of 32,768 µs, the system clock frequency (ø)
must be 0.5 MHz, 1 MHz, or 2 MHz.
H
) corresponds to the data in PWDRU and PWDRL.
t
ø
/2
0
/PWM is designated for PWM