5 Configuration Pin
5.2 Configuration Pin Function and Application
UG290-2.5.2E
17(98)
Pin Name
Functional Description
As an output configuration pin, it indicates that the FPGA can be
configured or not. If the FPGA meets the configuration condition, the
READY signal is high. If the configuration fails, READY signal is low.
As an input configuration pin, you can delay the configuration via its
own logic or by pulling down the READY signal.
As a GPIO, it can be used as an input or output type.
If READY is
used as an input GPIO, the initial value needs to be 1 before
configuration. Otherwise, the FPGA cannot be configured.
DONE
In-out pins. A signal which indicates FPGA is configured
successfully, DONE is pulled up after successfully configuring.
As an output configuration pin, it indicates the current configuration
of FPGA: if configured successfully, the DONE signal is high and the
device enters into working state. if the configuration fails, the DONE
signal keeps low. As an input configuration pin, the user can delay
the entering of user mode via its own internal logic or by reducing the
DONE signal. When RECONFIG_N or READY signals are low,
DONE signal also keeps low. When configuring SRAM using JTAG
circuit, it does not need to take DONE signal into account.
As a GPIO, it can be used as an input or output type.
If DONE is
used as an input GPIO, the initial value of DONE should be 1
before configuring. Otherwise, the FPGA will fail to enter the
user mode after being configured.
MODE
GowinCONFIG modes selection pin. As the selection pin of
GowinCONFIG modes, MODE is an input pin that has internal weak
pull-up. The maximum bit width is 3 bits. When FPGA powers up or a
low level pulse triggers RECONFIG_N, the device enters the
corresponding GowinCONFIG mode in accordance with the MODE
value. The same MODE value of the different Gowin series of FPGA
products may have different configuration MODE. As the number of
pins for each package is different, some MODE pins are not all
bonded out, and the unbound MODE pins are grounded by default.
Please refer to the corresponding PINOUT manual for further details.
When MODE pins are used as GPIOs, they can be used as an input
or output type.
Note that when the MODE value changes, power-on again or
providing one low pulse for triggering RECONFIG_N is required for it
to take effect.
JTAGSEL_N
As a configuration pin, it is an input pin with internal weak pull-up. If
JTAG pins are set as a GPIO in the Gowin software, the JTAG pins
can become GPIOs after the device being powered up and
successfully configured. The JTAG pin configuration functions can
be recovered by pulling down JTAGSEL_N. The JTAG configuration
functions are always available if no JTAG pin reuse is set. As a
GPIO, it can be used as an input or output type.
Note!
The JTAGSEL_N pin and four JTAG pins (TCK, TMS, TDI, and TDO) are
exclusive. JTAG pins can only be used as configuration pins if JTAGSEL_N is
set as a GPIO. JTAGSEL_N can only be used as a configuration pin if JTAG
pins are set as GPIOs.
