GD32VF103 User Manual
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first shift 5-bit BYPASS instruction (5
’
b 11111) for BSD JTAG, and then shift normal 4-bit
instruction for RISC-V JTAG. Because of the data shift under BSD JTAG BYPASS mode,
adding 1 extra bit to the data chain is needed.
The BSD JTAG IDCODE is 0x790007A3.
10.2.3.
Debug reset
The JTAG-DP register are in the power on reset domain. The System reset initializes the
majority of the RISC-V. The NJTRST reset can reset JTAG TAP controller only.
10.3.
Debug hold function overview
10.3.1.
Debug support for power saving mode
When STB_HOLD bit in DBG control register (DBG_CTL) is set and entering the standby
mode, the clock of AHB bus and system clock are provided by CK_IRC8M, and the debugger
can debug in standby mode. When exit the standby mode, a system reset generated.
When DSLP_HOLD bit in DBG control register (DBG_CTL) is set and entering the Deep-
sleep mode, the clock of AHB bus and system clock are provided by CK_IRC8M, and the
debugger can debug in Deep-sleep mode.
When SLP_HOLD bit in DBG control register (DBG_CTL) is set and entering the sleep mode,
the clock of AHB bus for CPU is not closed, and the debugger can debug in sleep mode.
10.3.2.
Debug support for TIMER, I2C, WWDGT, FWDGT and CAN
When the core halted and the corresponding bit in DBG control register (DBG_CTL) is set,
the following behaved.
For TIMER, the timer counters stopped and hold for debug.
For I2C, SMBUS timeout hold for debug.
For WWDGT or FWDGT, the counter clock stopped for debug.
For CAN, the receive register stopped counting for debug.