![Hynix Semiconductor GMS81C5108 User Manual Download Page 58](http://html1.mh-extra.com/html/hynix-semiconductor/gms81c5108/gms81c5108_user-manual_2192989058.webp)
GMS81C5108
JUNE 2001 Ver 1.0
55
Figure 12-12 Example of PWM at 4MHz
Figure 12-13 Example of Changing the Period in Absolute Duty Cycle (@4MHz)
Example:
Timer1 @4Mhz,
4kHz -
20
%
duty PWM mode
LDM R3DR,#0000_XX1XB ;R31 output
LDM TM1,#0010_0000B ;pwm enable
LDM T1PWHR,#0000_1100B ;20% duty
LDM T1PPR,#1110_0111B ;period 250uS
LDM T1PDR,#1100_0111B ;duty 50uS
LDM RSR,#X1XX_XXXXB ;set pwm port.
LDM TM1,#0010_0011B ;timer1 start
X means don’t care
fxin
T1
PWM
~~
~~
~~
01
02
03
04
7F
80
81
3FF
01
02
~~
~~
~~
~~
~~
~~
~~
POL=1
PWM
POL=0
Duty Cycle [80
H
+1 x 250nS = 32.25uS]
Period Cycle [3FF
H
x 250nS = 256uS, 3.9kHz]
PWMHR = 0C
H
T1PPR = FF
H
T1PDR = 80
H
T1CK[1:0] = 00 (250nS)
PWM03
PWM02
PWM01
PWM00
T1PPR (8-bit)
T1PDR (8-bit)
Period
Duty
1
1
FF
H
0
0
80
H
00
00
Source
T1
PWM
POL=1
Duty Cycle
Period Cycle [0D
H
+1 x 2uS = 28uS, 35.7kHz]
P W M H R = 0 0
H
T 1P P R = 0 D
H
T 1P D R = 0 4
H
T 1C K [1 :0 ] = 1 0 (2 uS )
00 01
02
03
04
05
07
08
0A 0B 0C 0D 00 01 02
03
04
05 06
07
08
09
00
01
02 03
06
09
04
[04
H
+1 x 2uS = 10uS]
Duty Cycle
[04
H
+1 x 2uS = 10uS]
Period Cycle [09
H
+1 x 2uS = 20uS, 50kHz]
Duty Cycle
[04
H
+1 x 2uS = 10uS]
Write T1PPR to 09
H
Period changed
clock
Downloaded from
Elcodis.com
electronic components distributor