sc18is602b NXP Semiconductors, sc18is602b Datasheet - Page 6

• Manufacturer Part Number: sc18is602b
• Description: I2c-bus To Spi Bridge
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC18IS602B
Product data sheet
7.1.4 Read from buffer
the Function ID. There is no restriction on the number or combination of Slave Selects that
can be enabled for an SPI message. If more than one SSn pin is enabled at one time, the
user should be aware of possible contention on the data outputs of the SPI slave devices.
Table 3.
The data on the SPI port will contain the same information as the I
the slave address and Function ID. For example, if the message shown in
transmitted on the I
The SC18IS602B counts the number of data bytes sent to the I
automatically send this same number of bytes to the SPI bus. As the data is transmitted
from the MOSI pin, it is also read from the MISO pin and saved in the data buffer.
Therefore, the old data in the buffer is overwritten. The data in the buffer can then be read
back.
If the data from the SPI bus needs to be returned to the I
be completed by reading the data buffer.
A read from the data buffer requires no Function ID. The slave address with the R/W bit
set to a ‘1’ will cause the SC18IS602B to send the buffer contents to the I
The buffer contents are not modified during the read process.
A typical write and read from an SPI EEPROM is shown in
Fig 6.
Fig 7.
Fig 8.
write to buffer
S
7
0
SLAVE ADDRESS
I
SPI message
Read from buffer
2
S
Function ID 01h to 0Fh
C-bus message
SLAVE ADDRESS
All information provided in this document is subject to legal disclaimers.
6
0
2
C-bus, the SPI bus will send the message shown in
W
Rev. 5 — 3 August 2010
A
5
0
SPI data
FUNCTION
R
DATA 1
A
ID
DATA 1
4
0
A
Section 8
DATA 1
A
SS3
3
gives an example of an SPI read.
DATA n
A
002aac451
2
C-bus master, the process must
Section
SS2
A
2
2
SC18IS602B
C-bus port and will
DATA n
2
C-bus data, but without
I
8.
2
A
C-bus to SPI bridge
SS1
© NXP B.V. 2010. All rights reserved.
1
DATA n
Figure
002aac449
2
NA
C-bus master.
Figure 6
P
002aac448
7.
A
SS0
0
is
6 of 25
P