Datasheet

DIT4096
11
SBOS225A
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READ OPERATION
Figure 7 shows an illustration of the read operation for the
control port. You may read one register or buffer address at
a time, or use the auto-increment capability built into the
control port to perform block reads. A 16-bit header is first
written to the port, with the first byte being used to configure
control port operation and set the starting register or buffer
address. The second byte of the header is comprised of
“don’t care” bits, which can be set to either 0 or 1 without
affecting port operation.
The first byte of the header contains two control bits, R/W
and STEP, followed by a 6-bit address. For read operations,
R/W
= 1. The STEP bit determines the address step size for
the auto-increment operation. When STEP = 0, the address
is incremented by 1. When STEP = 1, the address is
incremented by 2. Incrementing by 1 is useful when reading
multiple control registers in sequence, or when reading both
left and right channel status data in sequence. Incrementing
by 2 is useful for reading just one channel of status data in
sequence.
The first output data byte occurs immediately after the 16-bit
header has been written. This byte contains the 8-bit data for
the register or buffer address pointed to by the first byte of
the header. To read a single address location,
CS is brought
high after the least significant bit of the first data byte is
clocked out of the port. For auto increment mode,
CS is kept
low to read successive register or buffer addresses.
Byte 0 Byte 1
Byte N
Header
Set CS = 1 here to read one register or buffer location.
Keep CS = 0 to enable auto-increment mode.
CS
CDIN
CDOUT
CCLK
R/WSTEPA5A4 A3A2A1A0
MSB LSB
BYTE 0:
BYTE DEFINITION
Auto-Increment Address Step Size: 0 = Increment Address by 1
1 = Increment Address by 2
Register or Buffer Address
Read/Write Control: Set to 1 for Read Operation
Byte 1: All 8 bits are Don’t Care. Set 0 or 1.
Bytes 2 through N: 8-Bit Register or Buffer data.
High Impedance
Byte 0 Byte 1
Register or Buffer Data
Ignore Until Next High-to-Low Transition of CS
FIGURE 7. Read Operation Format.
FIGURE 8. Serial Port Timing.
t
CSCR
t
SDS
t
SDH
t
CFDO
t
CSZ
t
CFCS
CS
CCLK
CDIN
CDOUT