Application Note
AN_289 FT51A Programming Guide
Version 1.0
Document Reference No.: FT_000962 Clearance No.: FTDI# 483
111
Copyright © 2015 Future Technology Devices International Limited
2.12.9
PWM_OUT_CLR_EN
Bit
Position
Bit Field Name
Type
Reset
Description
7..0
clr_en
R/W
0
PWM Out Clear Enable bits for each of
the 8 PWM channels.
Table 2.144 PWM Out Clear Enable Register
2.12.10
PWM_CTRL_BL_CMP8
Bit
Position
Bit Field Name
Type Reset Description
7..0
ctrl_bl_cmp8
R/W
0
Control block CMP8 value.
0 continuous
1 one shot
2-255 repeat specified number of
times
Table 2.145 PWM Control Block Register
This controls the number of times to repeat the PWM waveform. The control block is shared across
all 8 PWM channels.
2.12.11
PWM_INIT
Bit
Position
Bit Field Name
Type
Reset
Description
7..0
init
R/W
0
PWM Initialization register bits for
each of the 8 PWM channels.
Table 2.146 PWM Initialisation Register
2.12.12
Use Cases
The following section describes an example of how to generate a 4-pulse PWM waveform using the
FT51A, which toggles at the following counter states: 7, 8, 12, 14, 15, 16, 19, and 22.
Figure 2.9 Pulse Waveform generated by 8 comparators
In this example there are eight toggle events and all eight comparators are used. In this example,
the 16 bit counter is programmed to count 24 states and then restart, and four pulses are
generated.
