;Example 3 - 4. Bit Reversion ASM Listing for TMS320F240
;================================================================
; Fetch 128 Data sample points from I/O port 0
;================================================================
FTCH_DATA
LAR AR0, #128 ; AR0 = 128
; # of Samples for Bit Reversed Addressing
LAR AR1, #B0_SADR
; AR1 = Start Address of B0; Data Buffer
LAR AR2, #ADCFIFO1 ; AR2 = Value Converted from ADC
LAR AR3, #(B1_SADR+128)
; AR3 = B1_SADR + 128
LAR AR7, #127 ; AR7 = 128 - 1
MAR *, AR2 ; ARP = AR2
LDP #224 ; Set Bit 0 of ADCTRL1
SBIT1 ADCTRL1,B0_MSK ; Starts ADC converting
LDP #232 ; Set Bit 6 of T1CON
SBIT1 T1CON,B6_MSK ; Starts the GP Timer 1
CLR CSXM ; Disable sign extension mode
; while reading in data from ADC
FTCH_LP
EVIFR A,BIT7 ; Polling routine to wait for
BCND FTCH_LP,NTC ; T1PINT Flag to be Set
LDP #224
SBIT1 ADCTRL1,B0_MSK ; Restart the ADC
LACC *, 15, AR3 ; ACC = ADCFIFO1; ARP = AR3
SACH *+, 0, AR1 ; Value at location pointed by AR3
; = Value pointed to by AR2; ARP = AR1
SACH *BR0+, 0, AR7 ; Store sample into data buffer of B0 using
; bit reversed addressing; ARP = AR7
LDP #232
LACC EVIFRA ; ACC = Event Manager Interrupt Flag Register
SACL EVIFRA ; Clear the flag register
BANZ FTCH_LP,*-,AR2 ; Wait for next flag of T1PINT, or if 128
; samples have been collected, perform FFT
; ARP = AR2
SBIT0 T1CON,B6_MSK ; Stop GP timer 1 - for FFT
SPLK #0000h,T1CNT ; Clear GP timer 1 counter
SET CSXM ; Enable sign extension mode
