4 Configuration Pin
4.2 Configuration Pin Function and Application
UG290-2.3E
13(87)
Pin Name
Functional Description
For the LittleBee
®
Family of FPGA products, when MODE[2: 0]=001,
the JTAGSEL_N pin and the four JTAG pins (TCK, TMS, TDI, TDO)
can be set as GPIOs simultaneously, but the JTAG pin cannot be
recovered as a configuration pin by JTAGSEL_N. It can be
recovered when the device reenters the edit mode.
TCK
As a configuration pin, it is an input pin.
It is a serial clock input pin in the JTAG configuration mode. As a
GPIO, it can be used as an input or output type.
TMS
As a configuration pin, it is an input pin with internal weak pull-up.
It is a serial input pin in JTAG configuration mode. As a GPIO, it can
be used as an input or output type.
TDI
As a configuration pin, it is an input pin with internal weak pull-up.
It is a serial data input pin in JTAG configuration mode. As a GPIO, it
can be used as an input or output type.
TDO
As a configuration pin, it is an output pin.
It is a serial data output pin in JTAG configuration mode. As a GPIO,
it can be used as an input or output type.
SCLK
As a configuration pin, it is an input pin.
It is a clock input pin in SSPI, SERIAL, and CPU configuration
modes. As a GPIO, it can be used as an input or output type.
CLKHOLD_N
As a configuration pin, it is an input pin with internal weak pull-up.
It is a clock-locking pin in SSPI and CPU configuration modes: SCLK
is valid when the input is high, and SCLK is invalid when the input is
low. As a GPIO, it can be used as an input or output type.
SSPI_CS_N
As a configuration pin, it is an input pin with internal weak pull-up. It
is a chip selection signal in the SSPI configuration mode, active low.
As a GPIO, it can be used as an input or output type.
SI
As a configuration pin, it is an input pin. It is a serial data input pin in
the SSPI configuration mode. As a GPIO, it can be used as an input
or output type.
SO
As a configuration pin, it is an output pin. It is a serial data output pin
in the SSPI configuration mode. As a GPIO, it can be used as an
input or output type.