Sundance SMT941 - Manual (Page 25)

User Manual SMT941 Page 25 of 43 Last Edited: 23/08/2011 17:24:00
1 ‘1’ Secondary reference divider enabled
Setting Bit 6 Description FB_DIS
0 ‘0’ FB Divider is active
1 ‘1’ FB Divider is disabled
Setting Bit 7 Description FB_CML_SEL
0 ‘0’ FB is CMOS type
1 ‘1’ FB is CML type
Setting Bit 8 Description FB_INCLK_INV
0 ‘0’ Input clock for FB not inverted (normal/low speed mode)
1 ‘1’ Input for FB inverted (high speed mode)
Setting Bit 15:9 Description FB_COUNTER
0 ‘0’ FB Path integer counter
1
CLOCK Register 17 0x27.
Clock Register 17 0x27
Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1 RESET_HO
LD
SEL_DELA
Y
RESHAPE Reserved OUT_MUX_S
EL
Default ‘0’ ‘0’ ‘0’ ‘0’ ‘0’
0 FB_MUX_
SEL
PD_PLL FB_PHASE_ADJ
Default ‘0’ ‘0’ ‘000000’
Reset Register 17 0x27
Setting Bit 5:0 Description FB_PHASE_ADJ
0 ‘0’ Feedback phase adjustment
Setting Bit 6 Description PD_PLL
0 ‘0’ PLL in normal mode
1 ‘1’ PLL powered down
Setting Bit 7 Description FB_MUX_SEL
0 ‘0’ VCXO selected for clock tree and FB
1 ‘1’ External Clock selected for clock tree and FB
Setting Bit 8 Description OUT_MUX_SEL
0 ‘0’ VCXO selected
1 ‘1’ External clock selected
Setting Bit 10 Description RESHAPE
0 ‘0’ Reference clock reshaped
1 ‘1’ Reference clock not reshaped
Setting Bit 11 Description SEL_DELAY
0 ‘0’ Enables short delay for fast operation
1 ‘1’ Long delay – recommended for reference below 150mhz.
Setting Bit 12 Description RESET_HOLD
0 ‘0’ RESET or HOLD acts as nRESET pin