PCA9552_5 © Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet Rev. 05 — 9 March 2006 6 of 28
Philips Semiconductors
PCA9552
16-bit I
2
C-bus LED driver with programmable blink rates
6.2.1 Control Register definition
6.3 Register descriptions
6.3.1 INPUT0 - Input register 0
The Input register 0 reflects the state of the device pins (inputs LED0 to LED7). Writes to
this register will be acknowledged but will have no effect.
Remark: The default value ‘X’ is determined by the externally applied logic level (normally
logic 1) when used for directly driving LED with pull-up to V
DD
.
6.3.2 INPUT1 - Input register 1
The Input register 1 reflects the state of the device pins (inputs LED8 to LED15). Writes to
this register will be acknowledged but will have no effect.
Remark: The default value ‘X’ is determined by the externally applied logic level (normally
logic 1) when used for directly driving LED with pull-up to V
DD
.
Table 3: Register summary
B3 B2 B1 B0 Symbol Access Description
0000INPUT0 read only input register 0
0001INPUT1 read only input register 1
0010PSC0 read/write frequency prescaler 0
0011PWM0 read/write PWM register 0
0100PSC1 read/write frequency prescaler 1
0101PWM1 read/write PWM register 1
0110LS0 read/write LED0 to LED3 selector
0111LS1 read/write LED4 to LED7 selector
1000LS2 read/write LED8 to LED11 selector
1001LS3 read/write LED12 to LED15 selector
Table 4: INPUT0 - input register 0 description
Bit 7 6 5 4 3 2 1 0
Symbol LED7 LED6 LED5 LED4 LED3 LED2 LED1 LED0
Default XXXXXXXX
Table 5: INPUT1 - input register 1 description
Bit 7 6 5 4 3 2 1 0
Symbol LED15 LED14 LED13 LED12 LED11 LED10 LED9 LED8
Default XXXXXXXX
