ST AN2366 Application note

AN2366

Application note

Guidelines for migrating ST72F324 or ST72324 (ROM)

applications to ST72F324B or ST72324B (ROM)

Introduction

This application note provides information on using ST72F324B, ST72324B (ROM) microcontroller devices in applications originally designed for the ST72F324 and ST72324 (ROM) series.

Table 1. Migration cross-reference table

From To Description

ST72F324, ST72324

ST72F324B, ST72324B

8K to 32K program memory, 32-pin and 42-/44-pin

July 2009 Doc ID 12345 Rev 2 1/8

www.st.com

Contents AN2366

Contents

1 ST72F324 migration: feature overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Feature compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 VDD Rise time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 Asynchronous RESET

2.3 Oscillator pad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Performance improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Limitations summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2/8 Doc ID 12345 Rev 2

AN2366 ST72F324 migration: feature overview

1 ST72F324 migration: feature overview

Table 2. Feature overview

Feature

Package

Program memory 8K to 32K

RAM 384 bytes to 1 Kbyte

Operating supply 3.8V to 5.5V

I/Os

Power saving modes

Nested interrupts Yes

(1)

ST72F324 ST72324 ROM ST72F324B ST72324B ROM

(2)

TQFP44 (10x10) / SDIP42

TQFP32 (7x7) / SDIP32

32/24 Multifunction bidirectional lines

22/17 Alternate function lines

12/10 High sink outputs

Slow / Wait /

Active Halt / Halt

Slow / Wait /

Active Halt / Halt

Slow / Wait /

Active Halt /

(3)

Halt

Slow / Wait /

Active Halt /

Halt

(3)

MCC / RTC Yes

Watchdog Yes

16-bit timer (OC / IC / PWM)

2 Timers (3/3/2)

(4)

2 Timers (3/3/2) 2 Timers (3/3/2) 2 Timers (3/3/2)

S P I Ye s Ye s Ye s Ye s

SCI Yes Yes Yes Yes

ADC Yes Yes Yes

LV D Yes N o Ye s

(5)

Ye s

Emulator ST7MDT20J-EMU3 and ST7MTD20-DVP3 (for Flash devices only)

Programming tools ST7MDT20J-EPB and ST7MTD20-DVP3 (for Flash devices only)

1. Refer to the corresponding datasheets for more information.

2. SDIP42 / SDIP32 packages are valid only for non-automotive devices.

3. Exit from Active Halt mode available with external interrupts.

4. The TAOC2HR and TAOC2LR registers are write only; reading them will return undefined values and OCF2 flag in the TACSR register cannot be used (forced to ‘0’ by hardware).

5. Improved ADC accuracy.

6. For 8K and 16K devices, Readout Protection is not supported if LVD is enabled.

(5)

(6)

Doc ID 12345 Rev 2 3/8

+ 5 hidden pages