CSM32RV20 from Nanjing Zhongke Microelectronics, in a QFN-32-EP(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	PB1	bidirectional	General-purpose I/O port B bit 1. No dedicated alternate function listed.
2	PB0	bidirectional	General-purpose I/O port B bit 0. No dedicated alternate function listed.
3	PA15	bidirectional	GPIO PA15. Muxable to TIMER2_CH4N, UART4_TX or EXTI[15]; also provides the RF detection input.
4	PA14	bidirectional	GPIO PA14. Muxable to ADC trigger (ADC_TRI), TIMER2_CH4, UART4_RX or EXTI[14].
5	PA13	bidirectional	GPIO PA13. Muxable to TIMER2_CH3N or EXTI[13]; additional function: ADC voltage reference output REFP.
6	PA12	bidirectional	GPIO PA12. Muxable to TIMER2_CH3 or EXTI[12]; additional function: PGA input.
7	PA11	bidirectional	GPIO PA11. Muxable to TIMER2_BKIN, TIMER2_CH2N, UART3_TX or EXTI[11]; additional function: ADC voltage reference output REFN.
8	PA10	bidirectional	GPIO PA10. Muxable to TIMER1_BKIN, TIMER2_CH2, UART3_RX or EXTI[10]; additional function: ADC_IN9.
9	PA9	bidirectional	GPIO PA9. Muxable to TIMER1_CH1, UART1_TX, TIMER2_CH1N or EXTI[9]; additional function: ADC_IN8.
10	PA8	bidirectional	GPIO PA8. Muxable to I2C SDA, UART1_RX, TIMER2_CH1 or EXTI[8]; additional function: ADC_IN7.
11	NRST	input	External reset input, active-low. Drive low to reset the MCU.
12	PA7	bidirectional	GPIO PA7. Muxable to I2C SCL, SPI MOSI, TIMER1_CH4N or EXTI[7]; additional function: ADC_IN6.
13	PA6	bidirectional	GPIO PA6. Muxable to UART1_TX, SPI MISO, TIMER1_CH4 or EXTI[6]; additional function: ADC_IN5.
14	PA5	bidirectional	GPIO PA5. Muxable to UART1_RX, SPI SCK, TIMER1_CH3N or EXTI[5]; additional function: ADC_IN4.
15	PA4	bidirectional	GPIO PA4. Muxable to SPI MOSI, TIMER1_CH1IN, TIMER1_CH3, UART2_TX or EXTI[4]; additional function: ADC_IN3.
16	PA3	bidirectional	GPIO PA3. Muxable to SPI MISO, TIMER1_CH1N, TIMER1_CH2N, UART2_RX or EXTI[3]; additional function: ADC_IN2.
17	PA2	bidirectional	GPIO PA2. Muxable to SPI SCK, TIMER1_CH1, TIMER1_CH2 or EXTI[2].
18	PA1	bidirectional	GPIO PA1. Muxable to cJTAG TMSC, I2C SDA, TIMER1_CH1N or EXTI[1].
19	PA0	bidirectional	GPIO PA0. Muxable to cJTAG TCKC, I2C SCL, TIMER1_CH1 or EXTI[0].
20	VDD	power_in	Main power supply, 1.8-5.5 V (VDD ≤ 4.8 V for ADC full-scale operation).
21	PB13	bidirectional	GPIO PB13; additional function OSC_OUT (external crystal drive output).
22	PB12	bidirectional	GPIO PB12; additional function OSC_IN (external crystal input).
23	PB11	bidirectional	GPIO PB11; additional function COMP3 negative input (COMP3-).
24	PB10	bidirectional	GPIO PB10; additional function COMP3 positive input (COMP3+).
25	PB9	bidirectional	GPIO PB9; additional function COMP2 negative input (COMP2-).
26	PB8	bidirectional	GPIO PB8; additional function COMP2 positive input (COMP2+).
27	PB7	bidirectional	GPIO PB7; additional function COMP1 negative input (COMP1-).
28	PB6	bidirectional	GPIO PB6; additional function COMP1 positive input (COMP1+).
29	PB5	bidirectional	General-purpose I/O port B bit 5. No dedicated alternate function listed on this variant (E77Q6). On the E77N6 variant this pin is VCAP instead.
30	PB4	bidirectional	GPIO PB4; alternate function SPI2_MISO.
31	PB3	bidirectional	GPIO PB3; alternate function SPI2_MOSI.
32	PB2	bidirectional	GPIO PB2; alternate function SPI2_SCK.
33	VSS	power_in	Ground. Exposed thermal/ground pad on the bottom of the QFN package; must be soldered to PCB ground.

Key specifications

Parameter	Value
Manufacturer	Nanjing Zhongke Microelectronics
Package	QFN-32-EP(4x4)
Category	MCU
Pins	33

Ordering variants

Same part, different packaging or reel option.

CSM32RV20E77Q6
CSM32RV20E77N6

CAD (KiCad official)

Symbol: CSM32RV20
Footprint: Package_DFN_QFN:QFN-32-1EP_4x4mm_P0.4mm_EP2.9x2.9mm
3D model: QFN-32-EP(4x4) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`csm32rv20.step`	76 KB	You want the bare part, or you mark your own boards.
`csm32rv20-etched.step`	1.7 MB	You want the part with `CSM32RV20` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 406 faces against 72 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Nanjing Zhongke Microelectronics datasheet (235 pp, sha256 c175e7d3b3828530, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF