20
LTC1402
APPLICATIONS INFORMATION
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* 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
; ***************************************************************************
