bit_bang_uart.h File Reference

public methods for bit_bang_uart.c More...

Go to the source code of this file.

Defines
#define	NO_CHARACTER_RECEIVED   0xFF
Functions
void	bitBangOutput (unsigned char outputByte)
char	bitBangInput ()

---

Detailed Description

public methods for bit_bang_uart.c

Rev

363

Author

dsmith

Date

2010-03-19 10:55:06 -0700 (Fri, 19 Mar 2010)

URL

http://dsmith@ns.svnrepository.com/svn/hardware/fw/ZNP%20Examples/bit_bang_uart.h

---

Function Documentation

char bitBangInput

(

)

Blocking UART receiver. Called by BIT_BANG_RX_PORT Interrupt Service Routine upon detection of start bit (high to low transition). BIT_BANG_RX_BIT should be configured as high-low edge triggered interrupt. Receives a byte and then processes it.

Note:

BIT_BANG_RX_PORT, BIT_BANG_RX_BIT, DISABLE_BIT_BANG_RX_INTERRUPT(), and ENABLE_BIT_BANG_RX_INTERRUPT() must be defined. Modify accordingly for other hardware.

Precondition:

Oscillator configured for 8MHz

A high-to-low transition has occurred on BIT_BANG_RX_BIT

Returns:

the byte received

void bitBangOutput

(

unsigned char

outputByte

)

Transmits one byte out the specified pin

To Send a Byte

• Line is nominally at '1' (high)
• 1 Start bit = '0'
• Data, MSB first, LSB last. '1' = line high, '0' = line low
• 1 Stop bit = '1' (idle, or high)

  Note:

  BIT_BANG_RX_PORT, BIT_BANG_RX_BIT, DISABLE_BIT_BANG_RX_INTERRUPT(), and ENABLE_BIT_BANG_RX_INTERRUPT() must be defined. Modify accordingly for other hardware.

  Precondition:

  Oscillator configured for 8MHz

  port/bit configured for logic output.

  bit is high (logic '1')

  Parameters:

  byte

  the byte to output