sc18is602b NXP Semiconductors, sc18is602b Datasheet - Page 9

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

NXP Semiconductors
SC18IS602B
Product data sheet
7.1.10 GPIO Enable - Function ID F6h
7.1.9 GPIO Read - Function ID F5h
The state of the pins defined as GPIO may be read into the SC18IS602B data buffer using
the GPIO Read function.
Note that this function does not return the value of the GPIO. To receive the GPIO
contents, a one-byte Read Buffer command would be required. The value of the Read
Buffer command will return the following byte.
Table 7.
Data for pins not defined as GPIO are undefined.
A GPIO Read is always performed to update the GPIO data in the buffer. The buffer is
undefined after the GPIO data is read back from the buffer. Therefore, reading data from
the GPIO always requires a two-message sequence (GPIO Read, followed by Read
Buffer).
At reset, the Slave Select pins (SS0, SS1, SS2 and SS3) are configured to be used as
slave select outputs. If these pins are not required for the SPI functions, they can be used
as GPIO after they are enabled as GPIO. Any combination of pins may be configured to
function as GPIO or Slave Selects.
After the GPIO Enable function is sent, the ports defined as GPIO will be configured as
quasi-bidirectional.
The data byte following the F6h command byte will determine which pins can be used as
GPIO. A logic 1 will enable the pin as a GPIO, while a logic 0 will disable GPIO control.
Table 8.
Fig 13. GPIO Read
Fig 14. GPIO Enable
X
X
7
7
GPIO Read (F5h) bit allocation
GPIO Enable (F6h) bit allocation
All information provided in this document is subject to legal disclaimers.
X
X
6
6
S
S
SLAVE ADDRESS
SLAVE ADDRESS
Rev. 5 — 3 August 2010
X
X
5
5
W
W
X
X
4
4
A
A
F5h
F6h
SS3
SS3
3
3
A
A
DATA
DATA
SS2
SS2
2
2
SC18IS602B
002aac455
002aac456
I
2
A
A
C-bus to SPI bridge
P
P
SS1
SS1
© NXP B.V. 2010. All rights reserved.
1
1
SS0
SS0
0
0
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