ST7232AK2-Auto STMicroelectronics, ST7232AK2-Auto Datasheet - Page 123

• 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

ST7232Axx-Auto
Receiver
The SCI can receive data words of either 8 or 9 bits. When the M bit is set, word length is 9
bits and the MSB is stored in the R8 bit in the SCICR1 register.
Character reception
During a SCI reception, data shifts in least significant bit first through the RDI pin. In this
mode, the SCIDR register consists or a buffer (RDR) between the internal bus and the
received shift register (see
Procedure
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When a character is received:
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Clearing the RDRF bit is performed by the following software sequence done by:
1.
2.
The RDRF bit must be cleared before the end of the reception of the next character to avoid
an overrun error.
Break character
When a break character is received, the SCI handles it as a framing error.
Idle character
When an idle frame is detected, there is the same procedure as a data received character
plus an interrupt if the ILIE bit is set and the I bit is cleared in the CCR register.
Overrun error
An overrun error occurs when a character is received when RDRF has not been reset. Data
can not be transferred from the shift register to the RDR register as long as the RDRF bit is
not cleared.
When an overrun error occurs:
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The OR bit is reset by an access to the SCISR register followed by a SCIDR register read
operation.
Select the M bit to define the word length
Select the desired baud rate using the SCIBRR and the SCIERPR registers
Set the RE bit, this enables the receiver which begins searching for a start bit
The RDRF bit is set. It indicates that the content of the shift register is transferred to the
RDR.
An interrupt is generated if the RIE bit is set and the I bit is cleared in the CCR register
The error flags can be set if a frame error, noise or an overrun error has been detected
during reception.
An access to the SCISR register
A read to the SCIDR register
The OR bit is set
The RDR content is not lost
The shift register is overwritten
An interrupt is generated if the RIE bit is set and the I bit is cleared in the CCR register
Figure
53).
On-chip peripherals
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