TABLE 1. LP3943 REGISTER TABLE

Address (Hex)

Register Name

Read/Write

Register Function

0x00

Input 1

Read Only

LED0–7 Input Register

0x01

Input 2

Read Only

LED8–15 Input Register

0x02

PSC0

R/W

Frequency Prescaler 0

0x03

PWM0

R/W

PWM Register 0

0x04

PSC1

R/W

Frequency Prescaler 1

0x05

PWM1

R/W

PWM Register 1

0x06

LS0

R/W

LED0–3 Selector

0x07

LS1

R/W

LED4–7 Selector

0x08

LS2

R/W

LED8–11 Selector

0x09

LS3

R/W

LED12–15 Selector

BINARY FOMAT FOR INPUT REGISTERS (READ ONLY) — ADDRESS 0x00 and 0x01

Address 0x00

Bit #

76543210

Default value

XXXXXXXX

LED7

LED6

LED5

LED4

LED3

LED2

LED1

LED0

X = don’t care

Address 0x01

Bit #

7

6

5

4

3

2

1

0

Default value

X

X

X

X

X

X

X

X

LED15

LED14

LED13

LED12

LED11

LED10

LED9

LED8

X = don’t care

BINARY FORMAT FOR FREQUENCY PRESCALER AND PWM REGISTERS — ADDRESS 0x02 to 0x05

Address 0x02 (PSC0)

Bit #

76543210

Default value

00000000

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 #

76543210

Default value

10000000

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 #

76543210

Default value

00000000

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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