SC18IS600 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2017. All rights reserved.
Product data sheet Rev. 7.1 — 20 November 2017 13 of 30
NXP Semiconductors
SC18IS600
SPI to I
2
C-bus interface
6.5.2 Read N bytes from I
2
C-bus slave device
Once the host issues this command, the SC18IS600 will start an I
2
C-bus read transaction
on the I
2
C-bus to the specified slave address. Once the data is received, the SC18IS600
will place this data in the receiver buffer, and will generate an interrupt on the INT
pin. The
‘transaction completed’ status can be read in the I2CStat. Note that the data is not
returned until a Read Buffer command is performed (see Section 6.5.4 “
Read buffer”).
Note that the third byte sent by the host is the device slave address. The SC18IS600 will
ignore the least significant bit so a read will always be performed even if the least
significant bit is a ‘0’. The maximum number of bytes to be read is 96.
6.5.3 I
2
C-bus read after write
Once the host issues this command, the SC18IS600 will start a write transaction on the
I
2
C-bus to the specified slave address. Once the data is written, the SC18IS600 will read
data from the specified slave, place the data in the Receiver Buffer and generate an
interrupt on the INT
pin. The ‘transaction completed’ status can be read in I2CStat. Note
that the data is not returned until a ‘Read Buffer’ command is performed.
6.5.4 Read buffer
Fig 12. Read N bytes from I
2
C-bus slave device
NUMBER
OF BYTES
0x01
COMMAND
SLAVE ADDRESS
+ R
SPI host sends
CS
SCLK
MOSI
1slave address A[7:1]number of bytes D[7:0]command 0x01
002aab719
Fig 13. I
2
C-bus read after write
002aab720
NUMBER OF
WRITE
BYTES
0x02
COMMAND
SLAVE
ADDRESS
+ W
SPI host sends
DATA
WRITE
BYTE 0
DATA
WRITE
BYTE N
NUMBER OF
READ
BYTES
SLAVE
ADDRESS
+ R
Fig 14. Read buffer
002aab868
0x06
COMMAND
SPI host sends
DATA
BYTE 1
DATA
BYTE N
