For your consideration:
-- Title: SPI Master (spi_master_hw.jal)
-- Author: William Welch Copyright (c) 2009, all rights reserved.
-- Compiler: uncertain. FIXME
--
-- This file is part of jallib (http://jallib.googlecode.com)
-- Released under the ZLIB license (http://www.opensource.org/licenses/
zlib-license.html)
--
-- Description: SPI Master hardware control.
-- Routines for sending and receiving through the SPI in master mode
--
-- TODO: only tested in Master mode 00
--
-- SPI is full-duplex, so we exchange master and slave data byte
function spi_master_hw_exchange (byte in m_data) return byte is
var byte stat
SSPBUF = m_data
stat = SSPCON & 0x80
if ( stat != 0 ) then
-- FIXME how to report error???
return 0xFF
end if
while ( SSPSTAT_BF == 0 ) loop end loop
-- return slave data
return SSPBUF
end function
-- half-duplex convenience function. send data to slave, discard reply
procedure spi_master_hw'put(byte in data) is
var byte dummy
dummy = spi_master_hw_exchange(data)
end procedure
-- half-duplex convenience function. send 0xFF, get slave data
function spi_master_hw'get() return byte is
var byte data
data = spi_master_hw_exchange(0xFF)
return data
end function
-- SPI Master mode 0,0 example.
-- Note: check your datasheet -- TRIS settings, any SPI errata?
procedure _spi_init_mode00() is
var byte v
SSPCON = 0
v = SSPSTAT & 0x3F
SSPSTAT = v
v = v | 0x40 -- CKE = 1
SSPSTAT = v
v = SSPCON
v = v | 2 -- CKP=0, Master mode, OSC/64
SSPCON = v
SSPCON_SSPEN = 1
end procedure
Thank you,
William
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"jallib" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/jallib?hl=en
-~----------~----~----~----~------~----~------~--~---
