
p
ll
s
-
s
M
T
5 - 36
HMC704LP4E
v03.1211
8 GHz fractionaL-n PLL
For price, delivery, and to place orders: Hittite Microwave Corporation,20 Alpha Road, Chelmsford, MA 01824
Phone: 978-250-3343
Fax: 978-250-3373
Order On-line at www.hittite.com
Application Support: Phone: 978-250-3343 or apps@hittite.com
aUX SEriaL Port
The PLL also features a general purpose 16 bit Aux serial Port (AuxsPI). The auxiliary serial port may be used to con-
trol other chips if available, via the Open mode protocol.
The AuxsPI outputs the contents of
“Reg 05h” upon receipt of a frequency change command. The AuxsPIdata is out-
put at the AuxsPI clock rate which is fpd (
“Reg 05h”[6]). A single AuxsPI transfer requires 16 AuxsPI cycles plus 4
overhead cycles.
rEGiStEr MaP
table 13. reg 00h iD register (read only)
BIT
TYPE
NAME
W
DEFLT
DEsCRIPTION
[23:0]
RO
chip_ID
24
A7975h
PLL subsystem ID, 94075
table 13. reg 00h open Mode and HMc Mode reset Strobe register (Write only)
(Continued)
BIT
TYPE
NAME
W
DEFLT
DEsCRIPTION
[5]
WO
rst_swrst
1
-
strobe (WRITE ONLY) generates soft reset. Resets all digital and
registers to default states
table 13. reg 00h open Mode read address register (Write only) (Continued)
BIT
TYPE
NAME
W
DEFLT
DEsCRIPTION
[4:0]
WO
Open Mode Read Address
5
-
specifies address to read when in Open Mode 2 cycle read
table 14. reg 01h PoWErDn register
BIT
TYPE
NAME
W
DEFLT
DEsCRIPTION
[0]
R/W
chipen_pin_select
1
0
1 = chip enable via CEN pin, Reg01[0]=1 and CEN pin low puts
PLL in Power Down Mode, see Power Down Mode description
0 = PLL subsystem chip enable via sPI (rst_chipen_from_spi)
Reg01[1]
[1]
R/W
chipen_from_spi
1
Controls PLL subsystem Chip Enable (Power Down) if rst_chipen_
pin_select
Reg01[0]=0 and Reg01[1]=1 = chip enabled, CEN don’t care
Reg01[0]=0 and Reg01[1]=0 = chip disabled, CEN don’t care
see Power Down Mode description and csp_enable
[2]
R/W
Keep_Bias On
1
0
keeps internal bias generators on, ignores Chip enable control
[3]
R/W
Keep_PFD_on
1
0
keeps PFD circuit on, ignores Chip enable control
[4]
R/W
Keep_CP_On
1
0
keeps Charge Pump on, ignores Chip enable control
[5]
R/W
Keep_Ref_buf ON
1
0
keeps Reference buffer block on, ignores Chip enable control
[6]
R/W
Keep_VCO_on
1
0
keeps VCO divider buffer on, ignores Chip enable control
[7]
R/W
Keep_GPO_driver ON
1
0
keeps GPO output Driver ON, ignores Chip enable control
[8]
R/W
reserved
1
0
reserved