RM0312 datasheet(24/275 Pages) STMICROELECTRONICS

24 / 275 page

Single wire interface module (SWIM) and debug module (DM)

RM0312

24/275

DocID022352 Rev 3

Single wire interface module (SWIM) and debug

module (DM)

3.1

Introduction

In-circuit debugging mode or in-circuit programming mode are managed through a single

wire hardware interface featuring ultrafast memory programming. Coupled with an in-circuit

debugging module, it also offers a non-intrusive emulation mode, making the in-circuit

debugger extremely powerful, close in performance to a full-featured emulator.

3.2

Main features

•

Based on an asynchronous, high sink (8 mA), open-drain, bidirectional communication.

•

Allows reading or writing any part of memory space.

•

Access to CPU registers (A, X, Y, CC, SP). They are memory mapped for read or write

access.

•

Non intrusive read/write on the fly to the RAM and peripheral registers.

•

Device reset capability with status flag in the Reset status register (RST_SR).

SWIM pin can be used as a standard I/O with some restrictions if you also want to use it for

debug. The most secure way is to provide on the PCB a strap option.

Figure 3. SWIM pin connection

3.3

SWIM modes

After a power-on reset, the SWIM is reset and enters OFF mode.

OFF: Default state after power-on reset. The SWIM pin cannot be used by the

application as an I/O.

I/O: This state is entered by software writing to the SWD bit in the Global configuration

standard I/O pin. In case of a reset, the SWIM goes back to OFF mode.

SWIM: This state is entered when a specific sequence is performed on the SWIM pin.

In this state, the SWIM pin is used by the host tool to control the STM8 with 3

commands (SRST system reset, ROTF read on the fly, WOTF write on the fly).

Note:

Refer to the STM8 SWIM communication Protocol and Debug Module User Manual for a

description of the SWIM and Debug module (DM) registers. Refer also to the Description of

global configuration register (CFG_GCR) on page 23.

MCU

SWIM/PA0

Jumper selection for

debug purposes

I/O for application

SWIM interface for tools

RM0312 数据表(PDF) 24 Page - STMicroelectronics

RM0312 数据表(HTML) 24 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载