Mikroelektronika MIKROE-350 Fiche De Données

The mikroBasic PRO for AVR provides a library for communication with the
Microchip’s Port Expander MCP23S17 via SPI interface. Connections of the AVR
compliant MCU and MCP23S17 is given on the schematic at the bottom of this
page.

Note: Library uses the SPI module for communication. The user must initialize SPI
module before using the Port Expander Library.

Note: Prior to calling any of this library routines, Spi_Rd_Ptr needs to be initialized
with the appropriate SPI_Read routine.

Note: Library does not use Port Expander interrupts.

- Expander_Init 
- Expander_Read_Byte 
- Expander_Write_Byte 
- Expander_Read_PortA
- Expander_Read_PortB 
- Expander_Read_PortAB 
- Expander_Write_PortA
- Expander_Write_PortB 

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

dim SPExpanderRST as
sbit sfr external

Reset line.

dim SPExpanderRST as
sbit at PORTB.B0

dim SPExpanderRST as
sbit at PORTB.B0

Chip Select line.

dim SPExpanderCS 

sbit at PORTB.B1

dim
SPExpanderRST_Directi
on 

Direction of the Reset pin.

dim
SPExpanderRST_Directi
on 

as sbit at DDRB.B0

dim
SPExpanderCS_Direction
as sbit sfr external

Direction of the Chip
Select pin.

dim
SPExpanderCS_Directio
ns 

as sbit at DDRB.B1