AD7303 Analog Devices, AD7303 Datasheet - Page 15

• Manufacturer Part Number: AD7303
• Description: +2.7 V to +5.5 V, Serial Input, Dual Voltage Output 8-Bit DAC
• Manufacturer: Analog Devices

Specifications of AD7303

• Resolution (bits): 8bit
• Dac Update Rate: 833kSPS
• Dac Settling Time: 1.2µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

REV. 0
*
*
*
UPDATE
*
*
*
TRANSFER
*
WAIT
*
*Execute instruction
LDAA
LDAA
STAA
BSR
JMP
PSHX
PSHY
PSHA
LDAA
STAA
LDAA
STAA
LDX
LDY
BCLR
LDAA
STAA
LDAA
BPL
INX
CPX
BNE
BSET
PULA
PULY
PULX
RTS
#$18
#$53
SPCR
UPDATE
#$E000
#$00
DIN 1
#$AA
DIN 2
#DIN1
#$1000
PORTC,Y $80
0,X
SPDR
SPSR
WAIT
#DIN 2+1
TRANSFER
PORTC,Y $80
0, 0, 0, 1, 1, 0, 0, 0
SCLK and DIN enabled as outputs
SPI on, Master mode, CPOL=0, CPHA=0, Clock rate =E/32
Update AD7303 output.
Restart.
Save relevant registers.
Control Word "0, 0, 0, 0, 0, 0, 0, 0"
Load both DAC A and DAC B DAC registers from shift register
with internal reference selected.
Data Word "1, 0, 1, 0, 1, 0, 1, 0"
Stack pointer at first first byte to send via DIN 1.
Stack pointer at on chip registers.
Assert SYNC.
Get BYTE to transfer via SPI.
Write to DIN register to start transfer.
Wait for SPIF to be set to indicate that transfer has been completed.
SPIF is the MSB of the SPCR. SPIF is automatically reset if in a set
state when the status register is read.
Increment counter for transfer of second byte.
16 bits transferred?
If not, transfer second BYTE.
Bring SYNC back high.
Restore registers.
Return to main program.
–15–
AD7303