ST7232AK2-Auto STMicroelectronics, ST7232AK2-Auto Datasheet - Page 198

• Manufacturer Part Number: ST7232AK2-Auto
• Description: 8-bit MCU for automotive, 16 Kbyte Flash, 10-bit ADC, 4 timers, SPI, SCI
• Manufacturer: STMicroelectronics

Specifications of ST7232AK2-Auto

• Hdflash Endurance: 100 cycles, data retention
• Clock Sources: crystal/ceramic resonator oscillators and bypass for external clock
• Four Power Saving Modes: halt, active halt, wait and slow
• Main Clock Controller With: real time base, beep and clock-out capabilities
• Two 16-bit Timers With: 2 input captures, 2 output compares, PWM and pulse generator modes

Known limitations
15.1.7
15.1.8
198/201
SCI wrong break duration
Description
A single break character is sent by setting and resetting the SBK bit in the SCICR2 register.
In some cases, the break character may have a longer duration than expected:
- 20 bits instead of 10 bits if M = 0
- 22 bits instead of 11 bits if M = 1.
In the same way, as long as the SBK bit is set, break characters are sent to the TDO pin.
This may lead to generate one break more than expected.
Occurrence
The occurrence of the problem is random and proportional to the baudrate. With a transmit
frequency of 19200 baud (f
occurrence is around 1%.
Workaround
If this wrong duration is not compliant with the communication protocol in the application,
software can request that an idle line be generated before the break character. In this case,
the break duration is always correct assuming the application is not doing anything between
the idle and the break. This can be ensured by temporarily disabling interrupts.
The exact sequence is:
●
●
●
●
39-pulse ICC entry mode
For Flash devices, ICC mode entry using ST7 application clock (39 pulses) is not supported.
External clock mode must be used (36 pulses). Refer to the ST7 Flash Programming
Reference Manual.
Disable interrupts
Reset and set TE (IDLE request)
Set and reset SBK (break request)
Re-enable interrupts
CPU
= 8MHz and SCIBRR = 0xC9), the wrong break duration
ST7232Axx-Auto