STM32L021D4 datasheet(40/114 Pages) STMICROELECTRONICS

部件名	STM32L021D4

功能描述	Access line ultra-low-power 32-bit MCU Arm®-based Cortex®-M0, 16KB Flash, 2KB SRAM, 512B EEPROM, ADC, AES

PDF	114 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

40 / 114 page

Pin descriptions

STM32L021x4

40/114

DocID027982 Rev 5

----

VSS

(4)

----

VDD

(5)

1. VSS pins are connected to the exposed pad (see Figure 34: UFQFPN32 - 32-pin, 5x5 mm, 0.5 mm pitch ultra thin fine

pitch quad flat package outline).

2. Device reset input/internal reset output (active low).

3. Analog power supply.

4. On TSSOP14 package, VDDA is internally connected to VDD.

5. Digital and analog ground.

6. Digital power supply.

7. PA14 pin on TSSOP14 package acts as an output pin when the embedded bootloader is active (SPI1_MISO). On empty

devices (devices from factory), the bootloader is active due to the empty check mechanism (refer to RM0377 reference

manual). PA14 pin also acts as SWCLK. When programming devices in TSSOP14 for the first time, it is necessary to use

the "connect under reset" method and the SWD interface to disable the bootloader by driving this PA14/SWCLK pin.

Table 12. Pin definitions (continued)

Pin number

Pin name

(function

after reset)

Notes

Pin functions

Alternate functions Additional functions

STM32L021D4 数据表(PDF) 40 Page - STMicroelectronics