Texas Instruments TLV1562 User Manual
Page 33
Software Overview
27
Interfacing the TLV1562 Parallel ADC to the TMS320C54x DSP
Task 1.2:
Use channel B in differential input mode and an external clock source. Following
changes have to be done with the set-up of Task 1.1:
Table 14. Instruction in the Program Header (Step 1)
R10BIT_RESOLUT
.set 00001h ; enable 10-bit resolution
R8BIT_RESOLUT
.set 00000h
R4BIT_RESOLUT
.set 00000h
INTERNAL_CLOCK
.set 00000h
EXTERNAL_CLOCK
.set 00001h ; use external clock
AUTO_PWDN_ENABLE
.set 00000h ; disable auto power down
DIFF_INPUT_MODE
.set 00001h ; differential input mode
IME_CALIBRATION
.set 00000h ; no internal calibration
SME_CALIBRATION
.set 00000h ; no system calibration
Additional correction in the middle of the main program files (step 2):
@CR0_SEND = #(
PAIR_B
|MONO_INT|SINGLE_END|CLK_INTERNAL|NO_CALIB_OP);
@CR1_SEND = #(NO_SW_PWDN|NO_AUTO_PWDN|NO_2COMPLEMENT|NO_DEBUG|RES_10_BIT|RD_CONV_START);
CAUTION:
Changing statements in step 2 is not required, if they are
already defined in the header. For example, the statement
CLK_INTERNAL does not change to
CLK_EXTERNAL
in
step 2 because the clock source is defined in the program header
and therefore will be justified behind the step 2 instructions later
in the program. That is why in step 2 only the
CH1
-value is
replaced with
PAIR_B,
but nothing else has been specified.
8.4.1.6
Common Software for all Modes
The files CONSTANT.ASM and VECTORS.ASM include constant definitions and
the interrupt vector table. Those parameters are identical for all ADC modes.
Therefore, the two files will be used for each mode and are described next:
CONSTANT.ASM Definition of constant values as it is the bit code for different
ADC modes (CR0/1), the serial DAC send words and the
DSP memory saving locations
VECTORS.ASM
Interrupt vector table of the TMS320C542
CALIBRAT.ASM ADC
calibration procedure (except for mono interrupt driven
mode using RD, this mode has not implemented any
calibration so far)
8.5
Flow Charts and Comments for All Software Modes
The following paragraphs show the flow charts and include comments for all
software modes.
8.5.1
The Mono Interrupt Driven Mode Using RD to Start Conversion
The following descriptions explain the software for the data acquisition in
monomode. The required interface connections are shown in Figure 1.