GD32VF103 User Manual
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detected, the HXTAL will be automatically disabled. The HXTAL Clock Stuck interrupt Flag,
CKMIF, in the Clock Interrupt Register, RCU_INT, will be set and the HXTAL failure event will
be generated. This failure interrupt is connected to the Non-Maskable Interrupt, NMI, of the
RISC-V. If the HXTAL is selected as the clock source of CK_SYS, PLL and CK_RTC, the
HXTAL failure will force the CK_SYS source to IRC8M, the PLL will be disabled automatically.
If the HXTAL is selected as the clock source of PLL, the HXTAL failure will force the PLL
closed automatically. If the HXTAL is selected as the clock source of RTC, the HXTAL failure
will reset the RTC clock selection.
Clock output capability
The clock output capability is ranging from 0.09375 MHz to 108 MHz. There are several clock
signals can be selected via the CK_OUT0 Clock Source Selection bits, CKOUT0SEL, in the
Clock Configuration Register 0 (RCU_CFG0). The corresponding GPIO pin should be
configured in the properly Alternate Function I/O (AFIO) mode to output the selected clock
signal..
Table 5-1. Clock output 0 source select
Clock Source 0 Selection bits
Clock Source
00xx
NO CLK
0100
CK_SYS
0101
CK_IRC8M
0110
CK_HXTAL
0111
CK_PLL/2
1000
CK_PLL1
1001
CK_PLL2/2
1010
EXT1
1011
CK_PLL2
Voltage control
The 1.2V domain voltage in Deep-sleep mode can be controlled by DSLPVS[1:0] bit in the
Deep-sleep mode voltage register (RCU_DSV).
Table 5-2. 1.2V domain voltage selected in deep-sleep mode
DSLPVS[1:0]
Deep-sleep mode voltage(V)
00
1.2
01
1.1
10
1.0
11
0.9