Wire serial interface – Rainbow Electronics ATA5812 User Manual
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47
ATA5811/ATA5812 [Preliminary]
4689B–RKE–04/04
.
4-wire Serial Interface
The 4-wire serial interface consists of the Chip Select (CS), the Serial ClocK (SCK), the
Serial Data Input (SDI_TMDI) and the Serial Data Output (SDO_TMDO). Data is trans-
mitted/received bit by bit in synchronization with the serial clock.
Note:
If the output level on pin N_RESET is low, no data communication with the microcontrol-
ler is possible.
When CS is low and the transparent mode is inactive (T_MODE = 0), SDO_TMDO is in
a high-impedance state. When CS is low and the transparent mode is active
(T_MODE = 1), the RX data stream is available on pin SDO_TMDO.
Figure 39. Serial Timing
Table 36. Command Structure
Command
MSB
LSB
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Read TX/RX data buffer
0
0
0
x
x
x
x
x
Write TX/RX data buffer
0
0
1
x
x
x
x
x
Read control/status register
0
1
0
A4
A3
A2
A1
A0
Write control register
0
1
1
A4
A3
A2
A1
A0
OFF command
1
0
0
X
X
X
X
X
Delete IRQ
1
0
1
X
X
X
X
X
Not used
1
1
0
X
X
X
X
X
Not used
1
1
1
X
X
X
X
X
CS
SCK
SDI_TMDI
SDO_TMDO
T
Out_enable
T
Setup
X
MSB
T
Hold
X
MSB
T
Cycle
T
CS_setup
MSB-1
T
Out_delay
MSB-1
X
T
CS_disable
T
Out_disable
X
LSB
X
X
T
SCK_setup1
T
SCK_setup2
T
SCK_hold
X can be either V
il
or V
iH