Xilinx Virtex UltraScale+ FPGAs - Reset and Initialization

Table 10: LCPLL Attributes (cont'd)
Attributes Type Description
SDM_CFG0[15:0] 16-bit Reserved. Use the recommended value from the Wizard.
Bit Name Address Description
SDM_WIDTHSEL [10:9] This attribute sets the denominator of the fractional part of
the feedback divider:
2'b00: 24 bits.
2'b01: 20 bits.
2'b10: 16 bits.
2'b11: Reserved.
SDM_CFG1
16-bit Reserved. Use the recommended value from the Wizard.
SDM_CFG2 16-bit Reserved. Use the recommended value from the Wizard.
SDM_SEED_CFG0 16-bit Reserved. Use the recommended value from the Wizard.
SDM_SEED_CFG1 16-bit Reserved. Use the recommended value from the Wizard.
A_SDM_DATA_CFG0 16-bit Reserved. Use the recommended value from the Wizard.
A_SDM_DATA_CFG1 16-bit Reserved. Use the recommended value from the Wizard.
Reset and Initialization
The GTM transceiver must be inialized aer device power-up and conguraon before it can be
used. The GTM transmier (TX) and receiver (RX) can be inialized independently and in parallel
as shown in the following gure. The GTM transceiver TX and RX inializaon comprises three
steps:
1. Inializing the associated PLL driving TX/RX
2. Inializing the TX and RX datapaths (PMA + PCS)
The TX and RX in the GTM transceiver receive the clock through the LCPLL in the transceiver's
own Dual. In the power-on inializaon sequence, the LCPLL used by the TX and RX must be
inialized rst. The LCPLL used by the TX and RX is reset individually and its reset operaon
independent from TX and RX resets. The TX and RX datapaths must be inialized only aer the
associated LCPLL is locked.
Chapter 2: Shared Features
UG581 (v1.0) January 4, 2019 www.xilinx.com
Virtex UltraScale+ GTM Transceivers 23
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