PCA9552 Philips Semiconductors, PCA9552 Datasheet - Page 5

• Manufacturer Part Number: PCA9552
• Description: 16-bit I2C LED driver with programmable blink rates
• Manufacturer: Philips Semiconductors

Philips Semiconductors
DEVICE ADDRESSING
Following a START condition the bus master must output the
address of the slave it is accessing. The address of the PCA9552 is
shown in Figure 4. To conserve power, no internal pull-up resistors
are incorporated on the hardware selectable address pins and they
must be pulled HIGH or LOW.
The last bit of the address byte defines the operation to be
performed. When set to logic 1 a read is selected, while a logic 0
selects a write operation.
CONTROL REGISTER
Following the successful acknowledgement of the slave address,
the bus master will send a byte to the PCA9552 which will be stored
in the Control Register. This register can be read and written via the
I
The lowest 3 bits are used as a pointer to determine which register
will be accessed.
If the auto-increment flag (AI) is set, the four low order bits of the
Control Register are automatically incremented after a read or write.
This allows the user to program the registers sequentially. The
contents of these bits will rollover to ‘0000’ after the last register is
accessed.
When auto-increment flag is set (AI = 1) and a read sequence is
initiated, the sequence must start by reading a register different from
‘0’ (B3 B2 B1 B0
Only the 4 least significant bits are affected by the AI flag.
Unused bits must be programmed with zeroes.
2004 Oct 01
2
C-bus.
16-bit I
RESET STATE: 00h
2
C LED driver with programmable blink rates
0
1
0 0 0 0).
Figure 5. Control register
Figure 4. Slave address
0
1
FIXED
0
SLAVE ADDRESS
0
AUTO-INCREMENT FLAG
AI
0
REGISTER ADDRESS
A2
B3
HARDWARE SELECTABLE
A1 A0
B2
B1
R/W
B0
SW00898
su01420
5
Control Register definition
REGISTER DESCRIPTION
INPUT0 — INPUT REGISTER 0
The INPUT register 0 reflects the state of the device pins (inputs 0
to 7). Writes to this register will be acknowledged but will have no
effect.
NOTE: The default value “X” is determined by the externally applied
logic level, normally ‘1’ when used for directly driving LED with
pull-up to V
INPUT1 — INPUT REGISTER 1
The INPUT register 1 reflects the state of the device pins (inputs 8
to 15). Writes to this register will be acknowledged but will have no
effect.
NOTE: The default value “X” is determined by the externally applied
logic level, normally ‘1’ when used for directly driving LED with
pull-up to V
PSC0 — FREQUENCY PRESCALER 0
PSC0 is used to program the period of the PWM output.
The period of BLINK0
default
default
default
B3
0
0
0
0
0
0
0
0
1
1
bit
bit
bit
B2
0
0
0
0
1
1
1
1
0
0
LED
LED
DD
DD
15
7
7
X
7
X
7
1
.
.
B1
0
0
1
1
0
0
1
1
0
0
LED
LED
14
6
6
X
6
X
6
1
B0
0
1
0
1
0
1
0
1
0
1
(PSC0
LED
LED
REGISTER
13
X
X
5
5
5
5
1
INPUT0
INPUT1
PWM0
PWM1
NAME
PSC0
PSC1
LS0
LS1
LS2
LS3
44
LED
LED
12
X
X
4
4
4
4
1
1)
LED
LED
WRITE
WRITE
WRITE
WRITE
WRITE
WRITE
WRITE
WRITE
READ/
READ/
READ/
READ/
READ/
READ/
READ/
READ/
READ
READ
TYPE
11
X
X
3
3
3
3
1
LED
LED
PCA9552
10
X
X
2
2
2
2
1
Product data sheet
PRESCALER 0
PRESCALER 1
FREQUENCY
FREQUENCY
REGISTER 0
REGISTER 1
REGISTER 0
REGISTER 1
SELECTOR
SELECTOR
SELECTOR
SELECTOR
FUNCTION
REGISTER
LED 12–15
LED 8–11
LED 0–3
LED 4–7
LED
LED
INPUT
INPUT
PWM
PWM
1
1
X
9
1
X
1
1
LED
LED
0
0
X
8
0
X
0
1