Software SPI Library
The mikroPascal PRO for FT90x provides routines for implementing Software SPI communication. These routines are hardware independent and can be used with any MCU. The Software SPI Library provides easy communication with other devices via SPI: A/D converters, D/A converters, MAX7219, LTC1290, etc.
- SPI to Master mode
- Clock value = 20 kHz.
- Data sampled at the middle of interval.
- Clock idle state low.
- Data sampled at the middle of interval.
- Data transmitted at low to high edge.
The library configures SPI to the master mode, clock = 20kHz, data sampled at the middle of interval, clock idle state low and data transmitted at low to high edge.
Important :
The Software SPI library implements time-based activities, so interrupts need to be disabled when using it.
External dependencies of Software SPI Library
| The following variables must be defined in all projects using Software SPI Library: | Description : | Example : |
|---|---|---|
var SoftSpi_SDI : sbit; sfr; external; |
Data In line. | var SoftSpi_SDI : sbit at GPIO_PIN30_Bit; |
var SoftSpi_SDO : sbit; sfr; external; |
Data Out line. | var SoftSpi_SDO : sbit at GPIO_PIN29_bit; |
var SoftSpi_CLK : sbit; sfr; external; |
Clock line. | var SoftSpi_CLK : sbit at GPIO_PIN27_bit; |
Library Routines
Soft_SPI_Init
| Prototype |
procedure Soft_SPI_Init(); |
|---|---|
| Description |
Routine initializes the software SPI module. |
| Parameters |
None. |
| Returns |
Nothing. |
| Requires |
External dependencies of the library from the top of the page must be defined before using this function. |
| Example |
// Software SPI module connections var SoftSpi_CLK : sbit at GPIO_PIN27_bit; var SoftSpi_SDI : sbit at GPIO_PIN30_Bit; var SoftSpi_SDO : sbit at GPIO_PIN29_bit; // End Software SPI module connections ... Soft_SPI_Init(); // Initialize Soft_SPI |
| Notes |
None. |
Soft_SPI_Read
| Prototype |
function Soft_SPI_Read(data_ : byte) : byte; |
|---|---|
| Description |
This routine performs 3 operations simultaneously. It provides clock for the Software SPI bus, reads a byte and sends a byte. |
| Parameters |
|
| Returns |
Byte received via the SPI bus. |
| Requires |
Soft SPI must be initialized before using this function. See Soft_SPI_Init routine. |
| Example |
var data_read, data_send : byte; ... // Read a byte and assign it to data_read variable // (data_send byte will be sent via SPI during the Read operation) data_read := Soft_SPI_Read(data_send); |
| Notes |
None. |
Soft_SPI_Write
| Prototype |
procedure Soft_SPI_Write(sdata : byte); |
|---|---|
| Description |
This routine sends one byte via the Software SPI bus. |
| Parameters |
|
| Returns |
Nothing. |
| Requires |
Soft SPI must be initialized before using this function. See Soft_SPI_Init. |
| Example |
// Write a byte to the Soft SPI bus Soft_SPI_Write(0xAA); |
| Notes |
None. |
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