STC15W4K56S4-30I-LQFP64S from STC Micro, in a LQFP-64(10x10). 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	P5.3/TxD4_2	bidirectional	Port 5 bit 3, standard I/O. Alternate: UART4 transmit (TxD4) secondary mapping.
2	P0.5/AD5/T3/PWMFLT_2	bidirectional	Port 0 bit 5, standard I/O. Address/data bus AD5 in external memory mode; Timer3 external clock input (T3); PWM fault input alt-mapping.
3	P0.6/AD6/T4CLKO/PWM7_2	bidirectional	Port 0 bit 6, standard I/O. Address/data bus AD6; Timer4 clock output (T4CLKO); PWM channel 7 alt-mapping.
4	P0.7/AD7/T4/PWM2_2	bidirectional	Port 0 bit 7, standard I/O. Address/data bus AD7; Timer4 external input (T4); PWM channel 2 alt-mapping.
5	P6.0	bidirectional	Port 6 bit 0, standard bidirectional I/O.
6	P6.1	bidirectional	Port 6 bit 1, standard bidirectional I/O.
7	P6.2	bidirectional	Port 6 bit 2, standard bidirectional I/O.
8	P6.3	bidirectional	Port 6 bit 3, standard bidirectional I/O.
9	P1.0/ADC0/CCP1/RxD2	bidirectional	Port 1 bit 0. ADC channel 0; PCA/CCP capture/compare channel 1 (CCP1); UART2 receive (RxD2).
10	P1.1/ADC1/CCP0/TxD2	bidirectional	Port 1 bit 1. ADC channel 1; PCA/CCP channel 0 (CCP0); UART2 transmit (TxD2).
11	P4.7/TxD2_2	bidirectional	Port 4 bit 7, standard I/O. UART2 transmit alt-mapping (TxD2_2).
12	P1.2/ADC2/SS/ECI/CMPO	bidirectional	Port 1 bit 2. ADC channel 2; SPI slave-select (SS); PCA external clock input (ECI); on-chip comparator output (CMPO).
13	P1.3/ADC3/MOSI	bidirectional	Port 1 bit 3. ADC channel 3; SPI master-out-slave-in (MOSI).
14	P1.4/ADC4/MISO	bidirectional	Port 1 bit 4. ADC channel 4; SPI master-in-slave-out (MISO).
15	P1.5/ADC5/SCLK	bidirectional	Port 1 bit 5. ADC channel 5; SPI serial clock (SCLK).
16	P1.6/ADC6/RxD_3/XTAL2/MCLKO_2/PWM6	bidirectional	Port 1 bit 6. ADC channel 6; UART1 receive alt-mapping (RxD_3); external crystal output XTAL2; master-clock output alt (MCLKO_2); PWM channel 6.
17	P1.7/ADC7/TxD_3/XTAL1/PWM7	bidirectional	Port 1 bit 7. ADC channel 7; UART1 transmit alt-mapping (TxD_3); external crystal input XTAL1; PWM channel 7.
18	P5.4/RST/MCLKO/SS_3/CMP-	bidirectional	Port 5 bit 4 / external RESET input (RST) / master-clock output (MCLKO) / SPI slave-select alt (SS_3) / comparator negative input (CMP-). Default function is RST; selectable as GPIO via ISP flag.
19	VCC	power_in	Positive supply (Vcc). Operating range 2.5V-5.5V (5V grade). Decouple with 100nF close to the pin.
20	P5.5/CMP+	bidirectional	Port 5 bit 5, standard I/O. Comparator positive input (CMP+).
21	GND	power_in	Ground (0V) reference for supply and I/O.
22	P4.0/MOSI_3	bidirectional	Port 4 bit 0, standard I/O. SPI master-out-slave-in alt-mapping (MOSI_3).
23	P6.4	bidirectional	Port 6 bit 4, standard bidirectional I/O.
24	P6.5	bidirectional	Port 6 bit 5, standard bidirectional I/O.
25	P6.6	bidirectional	Port 6 bit 6, standard bidirectional I/O.
26	P6.7	bidirectional	Port 6 bit 7, standard bidirectional I/O.
27	P3.0/RxD/INT4/T2CLKO	bidirectional	Port 3 bit 0. UART1 receive (RxD); external interrupt 4 (INT4, falling-edge only); Timer2 clock output (T2CLKO). Used by the STC ISP loader for programming.
28	P3.1/TxD/T2	bidirectional	Port 3 bit 1. UART1 transmit (TxD); Timer2 external input (T2). Used by the STC ISP loader.
29	P3.2/INT0	bidirectional	Port 3 bit 2 / external interrupt 0 (INT0), rising- and falling-edge sensitive. Can wake MCU from power-down.
30	P3.3/INT1	bidirectional	Port 3 bit 3 / external interrupt 1 (INT1), rising- and falling-edge sensitive. Can wake MCU from power-down.
31	P3.4/T0/T1CLKO/ECI_2	bidirectional	Port 3 bit 4. Timer0 external input (T0); Timer1 clock output (T1CLKO); PCA external clock alt-mapping (ECI_2).
32	P5.0/RxD3_2	bidirectional	Port 5 bit 0. UART3 receive alt-mapping (RxD3_2).
33	P5.1/TxD3_2	bidirectional	Port 5 bit 1. UART3 transmit alt-mapping (TxD3_2).
34	P3.5/T1/T0CLKO/CCP0_2	bidirectional	Port 3 bit 5. Timer1 external input (T1); Timer0 clock output (T0CLKO); PCA/CCP channel 0 alt-mapping (CCP0_2).
35	P3.6/INT2/RxD_2/CCP1_2	bidirectional	Port 3 bit 6 / external interrupt 2 (INT2, falling-edge only); UART1 receive alt (RxD_2); PCA/CCP channel 1 alt (CCP1_2).
36	P3.7/INT3/TxD_2/PWM2	bidirectional	Port 3 bit 7 / external interrupt 3 (INT3, falling-edge only); UART1 transmit alt (TxD_2); PWM channel 2.
37	P7.0	bidirectional	Port 7 bit 0, standard bidirectional I/O.
38	P7.1	bidirectional	Port 7 bit 1, standard bidirectional I/O.
39	P7.2	bidirectional	Port 7 bit 2, standard bidirectional I/O.
40	P7.3	bidirectional	Port 7 bit 3, standard bidirectional I/O.
41	P4.1/MISO_3	bidirectional	Port 4 bit 1. SPI master-in-slave-out alt-mapping (MISO_3).
42	P4.2/WR/PWM5_2	bidirectional	Port 4 bit 2. External memory write strobe (/WR); PWM channel 5 alt-mapping.
43	P4.3/SCLK_3	bidirectional	Port 4 bit 3. SPI clock alt-mapping (SCLK_3).
44	P4.4/RD/PWM4_2	bidirectional	Port 4 bit 4. External memory read strobe (/RD); PWM channel 4 alt-mapping.
45	P2.0/A8/RSTOUT_LOW	bidirectional	Port 2 bit 0. External memory address bus A8; MCU reset-output-low pin (drives low during reset, tri-state after) for peripheral reset.
46	P2.1/A9/SCLK_2/PWM3	bidirectional	Port 2 bit 1. Address bus A9; SPI clock alt (SCLK_2); PWM channel 3.
47	P2.2/A10/MISO_2/PWM4	bidirectional	Port 2 bit 2. Address bus A10; SPI MISO alt (MISO_2); PWM channel 4.
48	P2.3/A11/MOSI_2/PWM5	bidirectional	Port 2 bit 3. Address bus A11; SPI MOSI alt (MOSI_2); PWM channel 5.
49	P2.4/A12/ECI_3/SS_2/PWMFLT	bidirectional	Port 2 bit 4. Address bus A12; PCA external clock alt (ECI_3); SPI slave-select alt (SS_2); PWM fault-input (PWMFLT, stops PWM when asserted).
50	P2.5/A13/CCP0_3	bidirectional	Port 2 bit 5. Address bus A13; PCA/CCP channel 0 alt-mapping (CCP0_3).
51	P2.6/A14/CCP1_3	bidirectional	Port 2 bit 6. Address bus A14; PCA/CCP channel 1 alt-mapping (CCP1_3).
52	P2.7/A15/PWM2_2	bidirectional	Port 2 bit 7. Address bus A15; PWM channel 2 alt-mapping (PWM2_2).
53	P7.4	bidirectional	Port 7 bit 4, standard bidirectional I/O.
54	P7.5	bidirectional	Port 7 bit 5, standard bidirectional I/O.
55	P7.6	bidirectional	Port 7 bit 6, standard bidirectional I/O.
56	P7.7	bidirectional	Port 7 bit 7, standard bidirectional I/O.
57	P4.5/ALE/PWM3_2	bidirectional	Port 4 bit 5. External memory address-latch-enable (ALE) strobe; PWM channel 3 alt-mapping (PWM3_2).
58	P4.6/RxD2_2	bidirectional	Port 4 bit 6. UART2 receive alt-mapping (RxD2_2).
59	P0.0/AD0/RxD3	bidirectional	Port 0 bit 0. External memory address/data bus AD0; UART3 receive (RxD3).
60	P0.1/AD1/TxD3	bidirectional	Port 0 bit 1. Address/data bus AD1; UART3 transmit (TxD3).
61	P0.2/AD2/RxD4	bidirectional	Port 0 bit 2. Address/data bus AD2; UART4 receive (RxD4).
62	P0.3/AD3/TxD4	bidirectional	Port 0 bit 3. Address/data bus AD3; UART4 transmit (TxD4).
63	P0.4/AD4/T3CLKO	bidirectional	Port 0 bit 4. Address/data bus AD4; Timer3 clock output (T3CLKO).
64	P5.2/RxD4_2	bidirectional	Port 5 bit 2. UART4 receive alt-mapping (RxD4_2).

Key specifications

Parameter	Value
Manufacturer	STC Micro
Package	LQFP-64(10x10)
Category	MCU
Pins	64

Ordering variants

Same part, different packaging or reel option.

STC15W4K56S4-30I-LQFP64S
STC15W4K56S4-30I-LQFP64L
STC15W4K56S4-30I-LQFP64SQFN64
STC15W4K56S4-30I-LQFP48
STC15W4K56S4-30I-LQFP44
STC15W4K56S4-30I-LQFP64SPDIP40
STC15W4K56S4-30I-LQFP64SSOP32
STC15W4K56S4-30I-LQFP32
STC15W4K56S4-30I-LQFP64SSOP28
STC15W4K56S4-30I-LQFP64SSKDIP28

CAD (KiCad official)

Symbol: STC15W4K56S4-30I-LQFP64S
Footprint: Package_QFP:LQFP-64_10x10mm_P0.5mm
3D model: LQFP-64(10x10) (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`stc15w4k56s4-30i-lqfp64s.step`	847 KB	You want the bare part, or you mark your own boards.
`stc15w4k56s4-30i-lqfp64s-etched.step`	7.2 MB	You want the part with `STC15W4K56S4-30I-LQFP64S` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 1766 faces against 995 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 (1116 pp, sha256 5fbdfd823a6ce7e0, 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