Rainbow Electronics MAX7032 User Manual
Page 20
MAX7032
Low-Cost, Crystal-Based, Programmable,
ASK/FSK Transceiver with Fractional-N PLL
20
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CS
DIO
SCLK
CS
DIO
SCLK
0
0
0
0
0
0
0
0
A3
A2
A1
A0
READ
COMMAND
READ
COMMAND
ADDRESS
DATA
R7
R6
R5
R4
R3
R2
R1
R0
R0
R7
REGISTER DATA
REGISTER
DATA
0
0
0
0
0
0
0
0
A3
A2
A1
A0
ADDRESS
DATA
R7
R6
R5
R4
R3
R2
R1
REGISTER DATA
A3
16 BITS OF DATA
8 BITS OF DATA
1
0
A5
A4
1
0
A5
A4
Figure 9. Read Command on a 3-Wire Serial Interface
C1
C0
A5
A4
A3
A2
A1
A0
D3
D2
D1
D0
D7
D6
D5
D4
COMMAND
ADDRESS
DATA
CS
DIO
SCLK
Figure 8. Data Input Diagram
DIO is selected as an output of the MAX7032 for the fol-
lowing CS cycle whenever a READ command is
received. The CPU must tri-state the DIO line on the
cycle of CS that follows a read command, so the
MAX7032 can drive the data output line. Figure 9
shows the diagram of the 3-wire interface. Note that the
user can choose to send either 16 cycles of SLCK or
just eight cycles as all the registers are 8-bits wide. The
user must drive DIO low at the end of the read
sequence.
The MASTER RESET command (0x3) (see Table 2)
sends a reset signal to all the internal registers of the
MAX7032 just like a power-off and power-on sequence
would do. The reset signal remains active for as long as
CS is high after the command is sent.