DocID026046 Rev 1

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AN4457

UART emulator description

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UART emulator block diagram

Figure 1: UART emulator block diagram gives an overview of the interaction between the

hardware peripherals and the software modules that make up the UART emulator:

•

Software modules

They include the routines used for transmitting/receiving data and for formatting the

data to be sent by DMA or stored into SRAM. Flags indicating the UART status are also

available:

–

TC: Transmission Complete

This flag is set by software when data transmission is complete.

–

RC: Reception Complete

This flag is set by software when data reception is complete.

–

FE: Framing Error

This flag allows frame error detection.

–

PE: Parity Error

This flag is set by software when a parity error occurs in receive mode.

•

Hardware modules

They consist of all the STM32F4 peripherals involved in UART emulation:

–

GPIO: I/O ports used as transmitter or receiver pins.

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EXTI: in reception mode, the start bit falling edge is detected via an EXTI.

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DMA: data transfers are performed by DMA.

–

TIM: it ensures that data are transmitted and received at the required speed.

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SRAM: data are formatted and stored in the SRAM.

Figure 1. UART emulator block diagram

1. The status flags and the error flags are shown in green and red, respectively.