PCA9552 データシートの表示（PDF） - Philips Electronics
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PCA9552 Datasheet PDF : 21 Pages
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Philips Semiconductors
16-bit I2C LED driver with programmable blink rates
Product data sheet
PCA9552
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.
SLAVE ADDRESS
1 1 0 0 A2 A1 A0 R/W
FIXED
HARDWARE SELECTABLE
su01420
Figure 4. Slave address
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
I2C-bus.
0 0 0 AI B3 B2 B1 B0
RESET STATE: 00h
REGISTER ADDRESS
AUTO-INCREMENT FLAG
SW00898
Figure 5. Control register
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 0 0 0 0 0).
Only the 4 least significant bits are affected by the AI flag.
Unused bits must be programmed with zeroes.
Control Register definition
B3
B2
B1
B0
REGISTER
NAME
0 0 0 0 INPUT0
0 0 0 1 INPUT1
0010
PSC0
0011
PWM0
0100
PSC1
0101
PWM1
0110
LS0
0111
LS1
1000
LS2
1001
LS3
TYPE
READ
READ
READ/
WRITE
READ/
WRITE
READ/
WRITE
READ/
WRITE
READ/
WRITE
READ/
WRITE
READ/
WRITE
READ/
WRITE
REGISTER
FUNCTION
INPUT
REGISTER 0
INPUT
REGISTER 1
FREQUENCY
PRESCALER 0
PWM
REGISTER 0
FREQUENCY
PRESCALER 1
PWM
REGISTER 1
LED 0–3
SELECTOR
LED 4–7
SELECTOR
LED 8–11
SELECTOR
LED 12–15
SELECTOR
REGISTER DESCRIPTION
INPUT0 — INPUT REGISTER 0
LED LED LED LED LED LED LED LED
7
6
5
4
3
2
1
0
bit
7
6
5
4
3
2
1
0
default X X X X X X X X
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 VDD.
INPUT1 — INPUT REGISTER 1
LED LED LED LED LED LED LED LED
15 14 13 12 11 10 9
8
bit
7
6
5
4
3
2
1
0
default X X X X X X X X
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 VDD.
PSC0 — FREQUENCY PRESCALER 0
bit
7
6
5
4
3
2
1
0
default 1
1
1
1
1
1
1
1
PSC0 is used to program the period of the PWM output.
The
period
of
BLINK0
+
(PSC0 )
44
1)
2004 Oct 01
5
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