Smartcard mode functions

Smartcard mode functions. More...

Functions
void	USART_SetGuardTime (USART_TypeDef *USARTx, uint8_t USART_GuardTime)
	Sets the specified USART guard time. More...
void	USART_SmartCardCmd (USART_TypeDef *USARTx, FunctionalState NewState)
	Enables or disables the USART's Smart Card mode. More...
void	USART_SmartCardNACKCmd (USART_TypeDef *USARTx, FunctionalState NewState)
	Enables or disables NACK transmission. More...

Detailed Description

Smartcard mode functions.

 ===============================================================================
                               Smartcard mode functions
 ===============================================================================  

  This subsection provides a set of functions allowing to manage the USART 
  Smartcard communication.
  
  The Smartcard interface is designed to support asynchronous protocol Smartcards as
  defined in the ISO 7816-3 standard.

  The USART can provide a clock to the smartcard through the SCLK output.
  In smartcard mode, SCLK is not associated to the communication but is simply derived 
  from the internal peripheral input clock through a 5-bit prescaler.

  Smartcard communication is possible through the following procedure:
     1. Configures the Smartcard Prescaler using the USART_SetPrescaler() function.
     2. Configures the Smartcard Guard Time using the USART_SetGuardTime() function.
     3. Program the USART clock using the USART_ClockInit() function as following:
        - USART Clock enabled
        - USART CPOL Low
        - USART CPHA on first edge
        - USART Last Bit Clock Enabled
     4. Program the Smartcard interface using the USART_Init() function as following:
        - Word Length = 9 Bits
        - 1.5 Stop Bit
        - Even parity
        - BaudRate = 12096 baud
        - Hardware flow control disabled (RTS and CTS signals)
        - Tx and Rx enabled
     5. Optionally you can enable the parity error interrupt using the USART_ITConfig()
        function
     6. Enable the USART using the USART_Cmd() function.
     7. Enable the Smartcard NACK using the USART_SmartCardNACKCmd() function.
     8. Enable the Smartcard interface using the USART_SmartCardCmd() function.

  Please refer to the ISO 7816-3 specification for more details.


@note It is also possible to choose 0.5 stop bit for receiving but it is recommended 
      to use 1.5 stop bits for both transmitting and receiving to avoid switching 
      between the two configurations.
@note In smartcard mode, the following bits must be kept cleared:
        - LINEN bit in the USART_CR2 register.
        - HDSEL and IREN bits in the USART_CR3 register.
@note Smartcard mode is available on USART peripherals only (not available on UART4 
      and UART5 peripherals).

Function Documentation

void USART_SetGuardTime	(	USART_TypeDef *	USARTx,
		uint8_t	USART_GuardTime
	)

Sets the specified USART guard time.

Parameters

USARTx,:	where x can be 1, 2, 3 or 6 to select the USART or UART peripheral.
USART_GuardTime,:	specifies the guard time.

Return values

None

void USART_SmartCardCmd	(	USART_TypeDef *	USARTx,
		FunctionalState	NewState
	)

Enables or disables the USART's Smart Card mode.

Parameters

USARTx,:	where x can be 1, 2, 3 or 6 to select the USART or UART peripheral.
NewState,:	new state of the Smart Card mode. This parameter can be: ENABLE or DISABLE.

Return values

None

void USART_SmartCardNACKCmd	(	USART_TypeDef *	USARTx,
		FunctionalState	NewState
	)

Enables or disables NACK transmission.

Parameters

USARTx,:	where x can be 1, 2, 3 or 6 to select the USART or UART peripheral.
NewState,:	new state of the NACK transmission. This parameter can be: ENABLE or DISABLE.

Return values

None