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HMC700LP4 / 700LP4E
v11.0411
8 GHz 16-Bit Fractional-N PLL
Table 14. Reg 07h LKD/CSP Register
Bit
name
Width
Default
Description
[9:0]
wincnt_max
10
250
lock detect window
sets the number of consecutive counts of divided Vco that must land inside the
Lock Detect Window to declare LocK
[10]
lkd_enable
1
enables internal lock detect function, note output to Lock Detect Flag on LD_
SDO as per Figure 13 controlled by pfd_LD_opEn, Reg 0Bh PFD register
[11]
lkd_winasym_enable
1
0
asymmetrical window
enables lock detect window to only lag or only lead the
divided reference signal at the PFD, see Figure 9
[12]
lkd_win_asym_up_sel
1
0
1 selects lead window when lkd_winasym_enable=1
0 selects lag window when lkd_winasym_enable=1
[13]
ringosc_oneshot_sel
1
0
1 ring osc based one shot for lock detection mode
0 nominal 20nsec analog one shot for lock detection mode
[16:14]
oneshot_duration
3
0
duration of the ringosc based oneshot pulse in lock detection mode
[18:17]
ringosc_cfg
2
0
Lock Detect ringosc frequency trim
“00” fastest “11” slowest
[19]
ringosc_mode
1
0
force ringosc on
[20]
csp_enable
1
cycle slip prevention (cSP) enable
See section PFD Lock Detect for more information about this register.
Table 15. Reg 08h Analog EN Register
Bit
name
Width
Default
Description
[0]
bias_en
1
enables main chip bias reference
[1]
cp_en
1
charge pump enable
[2]
pfd_en
1
pfd enable
[3]
refbuf_en
1
reference path buffer enable. Set to 1 for normal operation.
[4]
vcobuf_en
1
vco path rF buffer enable
[5]
gpio_pads_en
1
gpio pads enable, Pins D0 and D1
required for use of GPo port or Vco Serial Port
[6]
sdo_pad_en
1
LD_SDo pad driver enable (Pin 5)
required for use of Lock Detect, Serial Port read operation
or Vco Serial Port operation
[7]
vcodiv_digclk_en
1
vco divider output clk to digital enable
[8]
vcodiv_en
1
enable vco divider
[9]
reserved
1
0
[10]
vcodiv_dutycyc_mode
1
0
vcodiv duty cycle mode
stretches the Vco divider output when n>32
[11]
reserved
1
0
Set to 0 for normal operation
[12]
rdiv_ref_to_dig_en
1
reference input applied to digital when set to 1, non-divided reference signal is
fed to digital (required for normal operation)
[13]
rdiv_refdiv_to_dig_en
1
reference divider applied to digital, when set to 1, divided reference signal is fed
to digital (required for normal operation)