AD8303AR Analog Devices Inc, AD8303AR Datasheet - Page 14

• Manufacturer Part Number: AD8303AR
• Description: IC DAC 12-BIT SERIAL 14-SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD8303AR

• Rohs Status: RoHS non-compliant
• Settling Time: 14µs
• Number Of Bits: 12
• Data Interface: Serial, SPI™
• Number Of Converters: 2
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 9.6mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL

AD8303
;AD8303.ASM
;
;
;
;
;
;
;
$MOD51
$TITLE(AD8303 Interface, Using the Serial Port in Mode 0)
;
;
;
PORT1
DAC_VAL0
DAC_VAL1
DAC_ADDR
LOOPCOUNT
SHIFTREG
SENDBYTE
DO_8303:
SEND_IT:
BYTESWAP:
SEND_WAIT:
This subroutine loads an AD8303 shift register with a 12-bit
Primary controls
Variable declarations
The DAC value is stored at location DAC-VAL1 (MSB) and DAC_VAL0 (LSB)
The DAC address (A or B) is stored at DAC_ADDR, (b0=0 for A, b1=0 for B)
DAC value, and transfers the value to DAC A or DAC B.
DATA
DATA
DATA
DATA
DATA
DATA
DATA
;
ORG
CLR
CLR
CLR
CLR
MOV
ACALL
MOV
ACALL
MOV
ANL
MOV
ORL
MOV
RET
;
;Convert the byte to LSB-first format and send it to the AD8303
MOV
MOV
RLC
MOV
MOV
RRC
MOV
DJNZ
MOV
JNB
CLR
RET
END
90H
40H
41H
42H
43H
44H
45H
100H
SCON.7
SCON.6
SCON.5
SCON.1
SHIFTREG,DAC_VAL1
SEND_IT
SHIFTREG,DAC_VAL0
SEND_IT
A,PORT1
A,DAC_ADDR
PORT1,A
A,#00000011B
PORT1,A
LOOPCOUNT,#8
A,SHIFTREG
A
SHIFTREG,A
A,SENDBYTE
A
SENDBYTE,A
LOOPCOUNT,BYTESWAP
SBUF,SENDBYTE
SCON.1,SEND_WAIT
SCON.1
Figure 35. Software Listing for the AD8303-80CL51 Interface
–14–
;SFR register for port 1
;LSBs of 12-bit DAC Value
; MSBs of DAC Value
;DAC address, format is:
; 1,1,1,1,1,1,LDB,LDA
;
;Count loops for byte swap
;Shift reg. for byte swap
; Destination reg. for SR
;arbitrary starting address
;set serial
;
;Clr SM2 for mode 0
;Clr the transmit flag
;Get Most Significant Byte
;
;Get Least Significant Byte
;
;Get I/O port contents
;Clr LDA/LDB, other bits unchanged
;Send to I/O port
;Set LDA and LDB high
;Send to I/O port
;Done
;Shift 8 bits
;Get source byte
;rotate MSB to carry
;Save new source byte
;get destination byte
;Move carry into MSB
;Save
;Done?
;Send the byte
;Wait until 8 bits are send
;Clear the serial flag
;Done
Set bit low to select DAC
data mode 0
send to AD8303
send it to the AD8303
REV. 0