sc18is602 NXP Semiconductors, sc18is602 Datasheet - Page 6

• Manufacturer Part Number: sc18is602
• Description: Sc18is602/sc18is603 I?c-bus To Spi Bridge
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC18IS602_603_3
Product data sheet
7.1.4 Read from buffer
Table 3.
[1]
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 SC18IS602/603 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 SC18IS602/603 to send the buffer contents to the I
master. The buffer contents are not modified during the read process.
A typical write and read from an SPI EEPROM is shown in
Fig 7. I
Fig 8. SPI message
Fig 9. Read from buffer
write to buffer
SS3 does not exist in the SC18IS603.
S
7
0
SLAVE ADDRESS
2
C-bus message
S
Function ID 01h to 0Fh
SLAVE ADDRESS
6
0
2
C-bus, the SPI bus will send the message shown in
Rev. 03 — 13 August 2007
W
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.
[1]
DATA n
A
002aac451
2
C-bus master, the process must
SC18IS602/603
Section
SS2
A
2
DATA n
2
2
C-bus data, but without
C-bus port and will
I
8.
A
2
C-bus to SPI bridge
SS1
© NXP B.V. 2007. All rights reserved.
1
DATA n
Figure
002aac449
NA
Figure 7
2
C-bus
P
002aac448
8.
A
SS0
is
0
6 of 25
P