
Multifunctional Peripheral Controller 2000
MFC2000
100723A
Conexant
13-1
13. General Purpose Inputs/Outputs (GPIO)
13.1 GPIO Signals
The AMFPC provides 31 GPIO lines (GPIO[30:0]) typically used for I/O control, each of which is multiplexed with
other signals. The direction of each GPIO line (input or output) is programmable using the hardware registers
shown in Section 13.3.
GPIO0
GPIO0 is multiplexed with the flash memory write enable signal
(FWRn) for the NAND-type flash memory, this GPIO0 pin is also
multiplexed with W_Rn.
This pin is selected as a GPIO when bit 2 of the GPIOConfig1 register
is set to 0 and Emulator signals are not enabled, in this case, the
direction of this pin is controlled by bit 0 of the GPIODir register. If
GPIODir[0] is set to one, this pin will ouput the value of the bit 0 from
GPIOData register, and, if GPIODir[0] is set to zero, the value of the
GPIO0 can be read back by reading GPIOdata[0].
This pin is selected as FWRn when the GPIOConfig1 bit is set to 1, in
this case, this pin becomes an output pin regardless of the value in the
GPIODir[0].
This pin is selected as W_Rn when EMUSIG_EN is set to 1, refer to
Testmgr section for EMUSIG_EN signal definition.
GPIO1 is multiplexed with the flash memory read enable signal
(FRDn) for the NAND-type flash memory, this GPIO1 pin is also
multiplexed with XAKn.
GPIO1
This pin is selected as a GPIO when bit 2 of the GPIOConfig1register
is set to 0 and, in this case, the direction of this pin is controlled by bit
1 of the GPIODir register. If GPIODir[1] is set to one, this pin will ouput
the value of the bit 1 from GPIOData register, and, if GPIODir[1] is set
to zero, the value of the GPIO1 can be read back by reading
GPIOdata[1].
This pin is selected as FWRn when the GPIOConfig1 bit is set to 1, in
this case, this pin becomes an output pin regardless of the value in the
GPIODir[1].
This pin is selecetd as XAKn when EMUSIG_EN is set to 1, refer to
Testmgr section for EMUSIG_EN signal definition.
GPIO2 is multiplexed with SSCLK2, this pin is also used for the DMA
request input from DMA channel 1 (DMAREQ1). If this pin is used as
DMAREQ1, the direction of this pin needs to be set as input.
GPIO2
If SSCLK2 function is used, the bit 0 of GPIOConfig2 register needs to
be set to 1. If this pin is used as SSCLK2, the GPIO2 direction and
data setting for this pin is no longer valid.
When bit 16 of GPIOCofig register is set to 0, this pin can be used as
GPIO2, in this case, the direction of this pin is controlled by bit 2 of the
GPIODir register. The GPIO2 input/output value is controlled by bit 2
of the GPIOData register.