20

LTC1402

* This is an example of how to initialize the Buffered Serial Port (BSP).

* The BSP is initialized to require an external CLK and FSX for

* operation. The data format is 16-bits, burst mode, with autobuffering

* enabled.

*

*

*****************************************************************************************************

*Timing at BSP pins in DSKPLUS TMS320c542 board with inverters at BCLKR and BFSR.

*

*BFSR Pin JP1-20 ~\___/~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\___/~~~~~~~~~~*

*BCLKR Pin JP1-14 _/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/

*

*BDR Pin JP1-26 -_—_—<REF-B11-B10-B09-B08-B07-B06-B05-B04-B03-B02-B01-B00>—_—_—<REF-B11-

*

*CLKIN Pin JP5-09 ~~~~~\_______/~~~~~~~\_______/~~~~~~~\_______/~~~~~~~\_______/~~~~~~~\_______/~~~~

*

*

*

*A 2 place right shift is needed to right justify the input data.

*

*The REF bit is also be masked in this example

*

*****************************************************************************************************

*

Loopback

.set

NO

;(digital looback mode?)

DLB bit

Format

.set

BIT_16

;(Data format? 16,12,10,8)

FO bit

IntSync

.set

NO

;(internal Frame syncs generated?)

TXM bit

IntCLK

.set

NO

;(internal clks generated?)

MCM bit

BurstMode

.set

YES

;(if BurstMode=NO, then Continuous)

FSM bit

CLKDIV

.set

3

;(3=default value, 1/4 CLOCKOUT)

PCM_Mode

.set

NO

;(Turn on PCM mode?)

FS_polarity

.set

NO

;(change polarity)YES=^^^\_/^^^, NO=___/^\___

CLK_polarity

.set

YES

;(change polarity)for BCLKR YES=_/^, NO=~\_

Frame_ignore

.set

!YES

;(inverted !YES -ignores frame)

XMTautobuf

.set

NO

;(transmit autobuffering)

RCVautobuf

.set

YES

;(receive autobuffering)

XMThalt

.set

NO

;(transmit buff halt if XMT buff is full)

RCVhalt

.set

NO

;(receive buff halt if RCV buff is full)

XMTbufAddr

.set

0x800

;(address of transmit buffer)

XMTbufSize

.set

0x000

;(length of transmit buffer)

RCVbufAddr

.set

0x800

;(address of receive buffer)

RCVbufSize

.set

0x800

;(length of receive buffer)works up to 800

*

*

*

**********************************************************************

.eval ((Loopback >> 1)|((Format & 2)<<1)|(BurstMode <<3)|(IntCLK <<4)|(IntSync <<5)) ,SPCval

.eval ((CLKDIV)|(FS_polarity <<5)|(CLK_polarity<<6)|((Format & 1)<<7)|(Frame_ignore<<8)|(PCM_Mode<<9)), SPCEval

.eval (SPCEval|(XMTautobuf<<10)|(XMThalt<<12)|(RCVautobuf<<13)|(RCVhalt<<15)), SPCEval

sineinit:

bspc = #SPCval

; places buffered serial port in reset

ifr = #10h

; clear interrupt flags

imr = #210h

; Enable HPINT,enable BRINT0

intm = 0

; all unmasked interrupts are enabled.

bspce = #SPCEval

; programs BSPCE and ABU

axr = #XMTbufAddr

; initializes transmit buffer start address

bkx = #XMTbufSize

; initializes transmit buffer size

arr = #RCVbufAddr

; initializes receive buffer start address

bkr = #RCVbufSize

; initializes receive buffer size

bspc = #(SPCval | GO)

; bring buffered serial port out of reset

return

;for transmit and receive because GO=0xC0

.space 16*32

;clear a chunk at the end to mark the end

;======================================================================

;

; VECTORS

;

;======================================================================

.sect “vectors”

;The vectors start here

;get BSP vectors

; ***************************************************************************

;

Vector Table for the ‘C54x DSKplus

;

BSP vectors and Debugger vectors

;

TDM vectors just return

; ***************************************************************************