Mikroelektronika MIKROE-742 데이터 시트

- Expander_Set_DirectionPortA
- Expander_Set_DirectionPortB 
- Expander_Set_DirectionPortAB 
- Expander_Set_PullUpsPortA
- Expander_Set_PullUpsPortB 
- Expander_Set_PullUpsPortAB

303

- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6

procedure Expander_Init(ModuleAddress : byte);

Nothing.

Initializes Port Expander using SPI communication.

Port Expander module settings : 

- hardware addressing enabled 
- automatic address pointer incrementing disabled (byte mode) 
- BANK_0 register adressing 
- slew rate enabled 

Parameters : 

- 

ModuleAddress

: Port Expander hardware address, see schematic at the bot-

tom of this page 

Global variables : 

- 

SPExpanderCS

: Chip Select line 

- 

SPExpanderRST

: Reset line 

- 

SPExpanderCS_Direction

: Direction of the Chip Select pin 

- 

SPExpanderRST_Direction

: Direction of the Reset pin 

must be defined before using this function. 

SPI module needs to be initialized. See SPI1_Init and SPI1_Init_Advanced routines. 

// Port Expander module connections
var SPExpanderCS  : sbit at PORTB.B1;

SPExpanderRST : 

sbit at PORTB.B0;

SPExpanderCS_Direction  : 

sbit at DDRB.B1;

SPExpanderRST_Direction : 

sbit at DDRB.B0;

// End of Port Expander module connections

...
SPI1_Init();               // initialize SPI module
Spi_Rd_Ptr := @SPI1_Read;  // Pass pointer to SPI Read function

of used SPI module

Expander_Init(0);          // initialize port expander