adate302-02 Analog Devices, Inc., adate302-02 Datasheet - Page 35

• Manufacturer Part Number: adate302-02
• Description: 500 Mhz Dual Integrated Dcl With Differential Drive/receive, Level Setting Dacs, And Per Pin Pmu
• Manufacturer: Analog Devices, Inc.

DEFINITION OF SPI WORD
The SPI can take variable length words, depending on the operation. At most, the word is 24 bits longs: 16 bits of data, two channel
selects, one R/W selector, and a 5-bit address.
Depending on the operation, the data can be smaller (or nonexistent in the case of a read operation).
Example 1
Write 16 bits of data to a register or DAC; unused MSBs are ignored. For example, Bit 15 and Bit 14 are ignored, while Bit 13 through Bit 0
are applied to the 14-bit DAC.
Example 2
Write 14 bits of data to the DAC.
Example 3a
Write two bits of data to the 2-bit register.
Example 3b
Write two bits of data to the 2-bit register. Bit 15 through Bit 2 are ignored, while Bit 1 through Bit 0 are applied to the register.
Example 4
Read request and follow with a 2
Table 18. Channel Selection
Channel 1
0
0
1
1
Table 19. R/W Definition
R/W
0
1
Channel 0
0
1
0
1
Channel Selected
NOP (no channel selected, no register changes)
Channel 0 selected
Channel 1 selected
Channel 0 and Channel 1 selected
Description
Current register specified by address is shifted out of SDOUT on next shift operation
Current data is written to register specified by address and channel select
nd
instruction (could be NOP) to clock out the data.
DATA[15:0]
DATA[15:0]
DATA[15:0]
DATA[13:0]
DATA[1:0]
CH[1:0]
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Figure 76.
Figure 77.
Figure 78.
Figure 79.
Figure 80.
R/W
CH[1:0]
CH[1:0]
CH[1:0]
CH[1:0]
CH[1:0]
ADDR[4:0]
R/W
R/W = 0
R/W
R/W
R/W
ADDR[4:0]
ADDR[4:0]
ADDR[4:0]
ADDR[4:0]
ADDR[4:0]
ADATE302-02