6 Configuration Mode Introduction
6.2 JTAG Configuration
UG290-2.5.2E
25(98)
Timing parameters of the Arora Family of FPGA Products are as
shown in Table 6-2.
Table 6-2 Timing Parameters for Power-on again and RECONFIG_N Triggering
(Arora Family)
Name
Description
Min.
Max.
T
portready
Time from application of V
CC
, V
CCX
and V
CCO
to the
rising edge of READY
-
23ms
T
recfglw
RECONFIG_N low pulse width
25ns
-
T
recfgtrdyn
Time from RECONFIG_N falling edge to READY
low
-
70ns
T
readylw
READY low pulse width
TBD
-
T
recfgtdonel
Time from RECONFIG_N falling edge to READY
low
-
80ns
6.2
JTAG Configuration
The JTAG configuration mode of Gowin FPGA products conforms to
the IEEE1532 standard and the IEEE1149.1 boundary scan standard.
The JTAG configuration mode writes bitstream data to the SRAM of
Gowin FPGA products. All configuration data is lost after the device is
powered down. All Gowin FPGA products support the JTAG configuration
mode.
6.2.1
JTAG Configuration Mode Pins
The relevant pins for the JTAG configuration mode are shown in Table
Table 6-3 Pin Description in JTAG Configuration Mode
Pin Name
I/O
Description
JTAGSEL_N
1
I, internal weak
pull-up
Revert JTAG pin from GPIO to configuration
pin. Low active
TCK 2
I
JTAG serial clock input
TMS
2
I, internal weak
pull-up
JTAG serial mode input
TDI
I, internal weak
pull-up
JTAG serial data input
TDO
O
JTAG serial data output
Note!
[1] The JTAGSEL_N works only when the JTAG pin is set as a GPIO and the device
starts to work. 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 editing mode.
[2] TCK needs to connect 4.7 K pull down resister on the PCB.