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GR716-DS-UM, May 2019, Version 1.29
284
www.cobham.com/gaisler
GR716
21
Dead band enable. 0b0 = Dead band time generation is disabled, no dead band time will be inserted when
the PWM output switch from deactive to active. 0b1 = Dead band time will be inserted when the PWM
output switch from deactive to active. Reset value is 0b0.
20:15
Interrupt scaler. Determines how many compare/period matches that need to occur before an interrupt is
generated. All zeroes means that an interrupt will occur every compare/period match, a one means that
an interrupt will occur every second match etc. Note that when generating a symmetric PWM two com-
pare matches occur during a PWM period but when generating an asymmetric PWM only one compare
match occur during a period. Reset value is 0b0..0 (all zeroes).
14
Interrupt type. 0b0 = Generate interrupt on PWM period match. 0b1 = Generate interrupt on PWM com-
pare match. Reset value is 0b0.
13
Interrupt enable/disable bit. 0b0 = Interrupt is disabled. 0b1 = Interrupt is enabled. Reset value is 0b0.
12:9
Reserved, always zero.
8
Dual compare mode enable. If this bit is set to 0b1 and the
meth
bit (see below) is set to 0b1 (symmetric)
then the core will update its internal PWM compare register twice every PWM period, once when the
counter is zero and once when a period match occur and the counter starts counting downwards again. In
this way it is possible to have two different compare values, one when counter is counting upwards and
one when counter is counting downwards. If this bit is 0b0 the compare register is only updated when the
counter is zero. This bit has no effect if an asymmetric PWM is generated. Reset value is 0b0.
7
When this pair_zero bit is set to 0b1 and the pair bit is set to 0b0 the complement output is always set to
zero. When this bit is set to 0b0 and the pair bit is set to 0b0 the complement output is inactive (depend-
ing on the polarity). When the pair bit is set to 0b1, this bit has no function.
6
PWM generation method select bit. This bit selects if an asymmetric or symmetric PWM will be gener-
ated, where 0b0 = asymmetric and 0b1 = symmetric. This bit can only be set if the PWM is disabled, i.e.
en
bit (see below) set to 0b0. The core prevents software from setting this bit to an invalid value. Reset
value is 0b0 if asymmetric PWM is supported otherwise 0b1.
5:3
PWM fix value select bits. These bits can be used to set the PWM output to a fix value. If bit 3 is set to
0b1 then bit 4 decides what value the PWM output will have. If the
pair
bit (see below) is set to 0b1
while bit 3 is set to 0b1 as well then bit 5 determines what value the complement output will have. Reset
value is 0b000.
2
PWM pair bit. If this bit is set to 0b1 a complement output for this PWM will be generated, creating a
PWM pair instead of a single PWM. The complement output will be the first ouput’s inverse, with the
exception that dead band time might be added when the values switch from deactive to active. Reset
value is 0b1.
1
PWM polarity select bit. 0b0 = PWM is active low, 0b1 = PWM is active high. This bit can only be set if
the PWM is disabled, i.e.
en
bit (see below) set to 0b0. Reset value equals
defpol
bit in
Capability
Regis-
ter 1
.
0
PWM enable/disable bit. 0b0 = PWM is disabled. 0b1 = PWM is enabled. When this bit is set to 1 (from
0) and the
wen
bit (see bit 9 above) is set the core’s internal address counter for the waveform RAM is
reset. Reset value is 0b0.
Table 344.
0x2C - PCTRL - PWM control register