UM0470 datasheet(4/37 Pages) STMICROELECTRONICS

Part #	UM0470

Description	STM8 SWIM communication protocol and debug module

PDF	37 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

4 / 37 page

Debug system overview

UM0470

4/37

Debug system overview

The STM8 debug system interface allows a debugging or programming tool to be connected

to the MCU through a single wire bidirectional communication based on open-drain line.

It provides non-intrusive read/write access to RAM and peripherals during program

execution

The block diagram is shown in Figure 1.

Figure 1.

Debug system block diagram

The debug module uses the two internal clock sources present in the device, the LSI Low

Speed Internal clock (usually in the range 30 kHz-200 kHz, depending on the product) one

and the HSI High Speed Internal clock (usually in the range 10 MHz to 25 MHz, depending

on the device). The clocks are automatically started when necessary.

SWIM Entry

LSI oscillator

HSI oscillator

Comm

Layer

Command

Decode

Debug module (DM)

STM8

Core

Peripherals

SWIM pin

CPU Bus

SWIM module

RAM

Flash/

STM8

Data EEPROM

UM0470 Datasheet(PDF) 4 Page - STMicroelectronics