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HMC703LP4E
v02.0813
8 GHz fractional syntHesizer
For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824
978-250-3343 978-250-3373 fax Order On-line at www.hittite.com
Application Support: pll@hittite.com
table 8. register 0 comparison - single vs Multi-User Modes
single User
HMC Mode
single Or Multi-User
Open Mode
READ
Chip ID
24 Bits
Chip ID
24Bits
WRITE
soft Reset,
General strobes
Read Address [4:0]
soft reset [5]
General strobes [24:6]
serial Port Mode Decision after Power-on reset
On power up, both types of modes are active and listening. All digital IO must be low at power-up.
A decision to select the desired serial Port mode (protocol) is made on the first occurrence of sEN or sCK , after which
the serial Port mode is fixed and only changeable by a power down.
a. If a rising edge on sEN is detected first HMC Mode is selected.
b. If a rising edge on sCK is detected first Open mode is selected.
serial Port HMc Mode - single Pll
HMC Mode (Legacy Mode) serial port operation can only address and communicate with a single PLL, and is compat-
ible with most HMC PLLs and PLLs with integrated VCOs.
The HMC Mode protocol for the serial port is designed for a 4 wire interface with a fixed protocol featuring
a. 1 Read/Write bit
b. 6 Address bits
c. 24 data bits
serial Port open Mode
The serial Port Open Mode features:
a. Compatibility with general serial port protocols that use a shift and strobe approach to
communication.
b. Compatible with HMC multi-Chip solutions, useful to address multiple chips of various types from a
single serial port bus.
The HMC Open Mode protocol has the following general features:
a. 3 bit chip address, can address up to 8 devices connected to the serial bus ( = 000 on
HMC703LP4E)
b. Wide compatibility with multiple protocols from multiple vendors
c. simultaneous Write/Read during the sPI cycle
d. 5 bit register address space
e. 3 wire for Write Only capability, 4 wire for Read/Write capability.
HMC RF PLLs with integrated VCOs also support HMC Open Mode. HMC700, HMC701, HMC702 and some genera-
tions of microwave PLLs with integrated VCOs do not support Open Mode.