RF6001_1 RFMD [RF Micro Devices], RF6001_1 Datasheet - Page 53

• Manufacturer Part Number: RF6001_1
• Description: FRACTIONAL-N RF SYNTHESIZER WITH MODULATOR AND DIGITAL IF FILTER
• Manufacturer: RFMD [RF Micro Devices]

Serial Data Interface and Device Control
A three wire serial data interface allows user programming of the internal control registers in the RF6001. The serial data inter-
face consists of the serial select (SSB), serial data in (SDI) and serial clock (SCLK) pins. The lock detect/test out (LDTO) pin is
by default configured as an output from the serial interface, but may be used to monitor various internal PLL signals, as well.
The serial interface contains a set of 32 18-bit registers that are individually accessed by 6-bit addresses.
The figure below shows a timing diagram for a serial transfer to the RF6001 serial data interface. Refer to the Electrical Speci-
fications for the timing margin requirements. The SSB pin is normally high. A serial transfer is initiated by taking SSB low. The
address and data bits on the SDI pin are shifted in on rising edges of the SCLK pin, MSB first. The data is latched and changes
take effect on the falling edge of the clock pulse corresponding to the last (18
fer is interrupted, such that the 18th data bit clock pulse does not occur, then no data is written to the register.
Data may be written to the registers in two ways: one register per serial transfer, or several sequential (adjacent) registers per
serial transfer. These actions are illustrated in the following figure.
The serial interface provides the capability of reading from the registers. If a register is written while the TEN SDI bit is set to
zero, then the previous contents of that register will be serially shifted out on the LDTO pin.
The following table illustrates the RF6001 Register Map. A serial transfer is initiated on the falling edge of SSB, and serial data
is shifted in MSB first, starting with the register address and then the data.
The RESET opcode (011111) is unique in that once the 011111 opcode is written, the RF6001 is reset, and held in reset until
the SSB pin is taken high. It is recommended to reset the RF6001 upon initial power-up of the system by writing the 011111
serial interface opcode. This ensures that the part will start up with the default register settings and that it will not be drawing
current unless enabled.
Rev A3 DS050929
Serial Write,
single address
Serial Write,
multiple, sequential addresses
LDTO
LDTO
SCLK
SCLK
SSB
SSB
SDI
SDI
SCLK
SSB
SDI
addr5
addr5
addr4
addr4
Tcs
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at ([phone] or [e-mail].
addr1
addr1
Tsu
addr(5)
Tcwh
addr0
addr0
data17
data17
Tcwl
addr(4)
Th
data17
data17
data16
data16
data16
data16
...
...
...
data15
data15
data2
data2
addr(0)
data2
data2
data1
data1
Part of the POLARIS™ TOTAL RADIO™ Solution
address is automatically
data1
MSB
data1
incremented to load
the next register
data0
data0
th
) data bit in the addressed register. If the trans-
data0
data0
data17
...
...
...
data17
data16
LSB
data16
data15
Tcs Tcs
data2
RF6001
data2
data1
data1
data0
data0
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