STC8G1K08-36I-SOP8 from STC Micro, in a SOP-8. 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	P5.4/nRST/MCLKO/INT2/T0/T1CLKO/RxD_3/MOSI/SCL_2	bidirectional	General-purpose I/O P5.4. Selectable functions: external reset input nRST (active low), master-clock divided output MCLKO, external interrupt INT2, Timer 0 external clock input T0, Timer 1 divided clock output T1CLKO, UART1 RX (mapping 3) RxD_3, SPI MOSI, and I2C clock SCL (secondary mapping). Supports quasi-bidirectional, push-pull, open-drain and high-impedance input modes with optional 4K pull-up.
2	VCC	power_in	Positive supply voltage input. Operating range typically 1.9 V to 5.5 V. Add a 10 µF bulk and 0.1 µF decoupling capacitor between VCC and GND close to the pin.
3	P5.5/INT3/T1/T0CLKO/TxD_3/SS/SDA_2	bidirectional	General-purpose I/O P5.5. Selectable functions: external interrupt INT3, Timer 1 external clock input T1, Timer 0 divided clock output T0CLKO, UART1 TX (mapping 3) TxD_3, SPI slave-select SS, and I2C data SDA (secondary mapping). Supports quasi-bidirectional, push-pull, open-drain and high-impedance input modes.
4	GND	power_in	Ground / 0 V reference for the device. Also serves as analog ground (AGND) reference for the ADC.
5	P3.0/RxD/INT4	bidirectional	General-purpose I/O P3.0. Selectable functions: UART1 default receive RxD and external interrupt INT4. Powers up in weak-pull-up (quasi-bidirectional) mode. Do not hold P3.0, P3.1 and P3.2 low simultaneously at power-up unless USB-ISP entry is desired.
6	P3.1/TxD	bidirectional	General-purpose I/O P3.1. Selectable function: UART1 default transmit TxD. Powers up in weak-pull-up (quasi-bidirectional) mode.
7	P3.2/INT0/SCLK/SCL/RxD_2	bidirectional	General-purpose I/O P3.2. Selectable functions: external interrupt INT0, SPI clock SCLK, I2C clock SCL (default mapping), and UART1 RX (mapping 2) RxD_2. Powers up in high-impedance input state.
8	P3.3/INT1/MISO/SDA/TxD_2	bidirectional	General-purpose I/O P3.3. Selectable functions: external interrupt INT1, SPI MISO, I2C data SDA (default mapping), and UART1 TX (mapping 2) TxD_2. Powers up in high-impedance input state.

Key specifications

Parameter	Value
Manufacturer	STC Micro
Package	SOP-8
Category	MCU
Pins	8

Ordering variants

Same part, different packaging or reel option.

STC8G1K08-36I-SOP8
STC8G1K08-36I-DFN8

CAD (KiCad official)

Symbol: STC8G1K08-36I-SOP8
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`stc8g1k08-36i-sop8.step`	122 KB	You want the bare part, or you mark your own boards.
`stc8g1k08-36i-sop8-etched.step`	3.9 MB	You want the part with `STC8G1K08-36I-SOP8` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 904 faces against 147 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: STC Micro datasheet (1240 pp, sha256 7d5e82c9f651aa92, 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