LP3943 Datasheet, PDF (9/13 Pages) National Semiconductor (TI) – RGB/White/Blue 16-LED Fun Light Driver

Application Notes (Continued)
Address (Hex)
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
TABLE 1. LP3943 REGISTER TABLE
Register Name
Input 1
Input 2
PSC0
PWM0
PSC1
PWM1
LS0
LS1
LS2
LS3
Read/Write
Read Only
Read Only
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Register Function
LED0–7 Input Register
LED8–15 Input Register
Frequency Prescaler 0
PWM Register 0
Frequency Prescaler 1
PWM Register 1
LED0–3 Selector
LED4–7 Selector
LED8–11 Selector
LED12–15 Selector
BINARY FOMAT FOR INPUT REGISTERS (READ ONLY) — ADDRESS 0x00 and 0x01
Bit #
Default value
X = don’t care
7
X
LED7
6
X
LED6
Address 0x00
5
X
LED5
4
X
LED4
3
X
LED3
2
X
LED2
1
X
LED1
0
X
LED0
Bit #
Default value
X = don’t care
7
X
LED15
6
X
LED14
Address 0x01
5
X
LED13
4
X
LED12
3
X
LED11
2
X
LED10
1
X
LED9
BINARY FORMAT FOR FREQUENCY PRESCALER AND PWM REGISTERS — ADDRESS 0x02 to 0x05
0
X
LED8
Address 0x02 (PSC0)
Bit #
7
6
5
4
3
2
1
0
Default value
0
0
0
0
0
0
0
0
PSC0 register is used to program the period of DIM0.
DIM0 = (PSC0+1)/160
The maximum period is 1.6s when PSC0 = 255.
Address 0x03 (PWM0)
Bit #
7
6
5
4
3
2
1
0
Default value
1
0
0
0
0
0
0
0
PWM0 register determines the duty cycle of DIM0. The LED outputs are LOW (LED on) when the count is less than the value in PWM0 and HIGH (LED off) when
it is greater. If PWM0 is programmed with 0x00, LED output is always HIGH (LED off).
The duty cycle of DIM0 is: PWM0/256
Default value is 50% duty cycle.
Address 0x04 (PSC1)
Bit #
7
6
5
4
3
2
1
0
Default value
0
0
0
0
0
0
0
0
PSC1 register is used to program the period of DIM1.
DIM1 = (PSC1 + 1)/160
The maximum period is 1.6s when PSC1 = 255.
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