SSC050-01 Datasheet, PDF (24/79 Pages) Maxim Integrated Products – Two-Wire Serial Backplane Controller

Control Registers
Control Register Definition
SSC050-01
Data Sheet
03h: General Purpose I/O Port 3 Data (GPD3)
Register Name:
Address:
Reset Value:
Description
GPD3
03h
XXXX_XXXXb
General Purpose I/O Port 3 Data
7
6
5
4
3
2
1
0
General Purpose Data
Bit(s) Bit Label
7:0
GPD0.7-0
Access Description
R/W When the I/O pin has been enabled as an output, writing these bits determines the
data value which will be present on the corresponding I/O pin. If the I/O pin has been
enabled as an input, reading these register bits will represent the current voltage
applied to the pin. At no time will the bits directly represent the value latched into the
data register. If a pin is enabled as an input and there is no signal applied, weak
internal pull-up resistors will hold the pin at a binary one. After a reset or power-on,
the register bits will be set to a binary one, but the value returned from a register
read will be the level applied to the pin since by default each pin is an input.
04h: General Purpose I/O Port 4 Data (GPD4)
Register Name:
Address:
Reset Value:
Description
GPD4
04h
XXXX_XXXXb
General Purpose I/O Port 4 Data
7
6
5
4
3
2
1
0
General Purpose Data
Bit(s) Bit Label
7:0
GPD0.7-0
Access Description
R/W When the I/O pin has been enabled as an output, writing these bits determines the
data value which will be present on the corresponding I/O pin. If the I/O pin has been
enabled as an input, reading these register bits will represent the current voltage
applied to the pin. At no time will the bits directly represent the value latched into the
data register. If a pin is enabled as an input and there is no signal applied, weak
internal pull-up resistors will hold the pin at a binary one. After a reset or power-on,
the register bits will be set to a binary one, but the value returned from a register
read will be the level applied to the pin since by default each pin is an input.
4-8
Revision 4.0
November 10, 2004