AD9510 Analog Devices, AD9510 Datasheet - Page 25

• Manufacturer Part Number: AD9510
• Manufacturer: Analog Devices

Preliminary Technical Data
The AD9510 uses Addresses 00h to 5Ah. Although the AD9510
serial control port allows for both 8-bit and 16-bit instructions,
the 8-bit instruction mode provides access only to five address
bits (A4 to A0), which restricts its use to the address space 00h
to 01F. The AD9510 defaults to 16-bit instruction mode on
power-up. The 8-bit instruction mode (although defined for
this serial control port) is not useful for the AD9510; therefore,
it is not discussed in this data sheet.
THE INSTRUCTION WORD (16 BITS)
The MSB of the instruction word is
whether the instruction will be a read or a write. The next two
bits, W1:W0, indicate the length of the transfer in bytes. The
final 13 bits are the address (A12:A0) at which to begin the read
or write operation. For a write, the instruction word is followed
by the number of bytes of data indicated by Bits W1:W0, which
is interpreted according to Table 17.
Table 17. Byte Transfer Count
W1
0
0
1
1
A12:A0: These 13 bits select the address within the register map
which is written to or read from during the data transfer
portion of the communications cycle. For multibyte transfers,
this address is the starting byte address. In MSB first mode,
subsequent bytes increment the address.
Table 18. Serial Control Port, 16-Bit Instruction Word, MSB First
MSB
I15
R/ W
I14
W1
W0
0
1
0
1
I13
W0
Bytes to Transfer
1
2
3
4
I12
A12
R/ W
I11
A11
, which indicates
I10
A10
I9
A9
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I8
A8
MSB/LSB FIRST TRANSFERS
The AD9510 instruction word and byte data may be MSB first
or LSB first. The default for the AD9510 is MSB first. The LSB
first mode may be set by writing 1 to Address 00h, Bit <6>. This
takes effect immediately (since it only affects the operation of
the serial control port) and does not require that an update be
executed. Immediately after the LSB first bit is set, all serial
control port operations are changed to LSB first order.
When MSB first mode is active, the instruction and data bytes
must be written from MSB to LSB. Multibyte data transfers in
MSB first format start with an instruction byte that includes the
register address of the most significant data byte. Subsequent
data bytes must follow in order from high address to low
address. In MSB first mode, the serial control port internal byte
address generator decrements for each data byte of the
multibyte transfer cycle.
When LSB_First = 1 (LSB first), the instruction and data bytes
must be written from LSB to MSB. Multibyte data transfers in
LSB first format start with an instruction byte that includes the
register address of the least significant data byte followed by
multiple data bytes. The serial control port internal byte address
generator increments for each byte of the multibyte transfer
cycle.
The AD9510 serial control port data address decrements from
the data address written toward 0x00 for multibyte I/O
operations if the MSB first mode is active. The serial control
port address increments from the data address written toward
0x1F for multibyte I/O operations if the LSB first mode is
active.
I7
A7
I6
A6
I5
A5
I4
A4
I3
A3
I2
A2
I1
A1
AD9510
LSB
I0
A0