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©2018 Integrated Device Technology, Inc
September 12, 2018
8A3xxxx Family Programming Guide
INPUT_TDC.INPUT_TDC_FBD_CTRL
Input TDC feedback divider control.
INPUT_TDC.INPUT_TDC_CTRL
Input TDC control
TRIGGER: Writing to this byte triggers a read and activation in hardware of all the bytes of the INPUT_TDC module.
Table 383: INPUT_TDC.INPUT_TDC_FBD_CTRL Bit Field Locations and Descriptions
Offset
Address
(Hex)
INPUT_TDC.INPUT_TDC_FBD_CTRL Bit Field Locations
D7
D6
D5
D4
D3
D2
D1
D0
004h
FBD_INTEG
ER_MODE_
EN[7]
FBD_INTEGER[6:0]
INPUT_TDC.INPUT_TDC_FBD_CTRL Bit Field Descriptions
Bit Field Name
Field Type Default Value
Description
FBD_INTEGER_MODE_E
N[7]
R/W
0
Input TDC feedback divider integer mode enable.
When set to '1', the value assigned to 'input_tdc_fbd_integer' field is used to
program the input TDC feedback divider. Otherwise, when set to '0', the input
TDC feedback divider will be programmed internally and the input TDC
frequency will be configured as 625 MHz.
0 = disabled
1 = enabled
FBD_INTEGER[6:0]
R/W
0
Input TDC feedback divider integer value.
ITDC_UI = 1 / (32 * input TDC frequency).
Table 384: INPUT_TDC.INPUT_TDC_CTRL Bit Field Locations and Descriptions
Offset
Address
(Hex)
INPUT_TDC.INPUT_TDC_CTRL Bit Field Locations
D7
D6
D5
D4
D3
D2
D1
D0
005h
RESERVED[7:3]
RESERVED[2:1]
REF_SEL[0]
INPUT_TDC.INPUT_TDC_CTRL Bit Field Descriptions
Bit Field Name
Field Type Default Value
Description
RESERVED
N/A
-
This field must not be modified from the read value
REF_SEL[0]
R/W
0
Control mux to forward either a XTAL or XO_DPLL reference towards Input
TDC. By default, a XTAL reference is forwarded towards it.
0 = XTAL
1 = XO_DPLL