Manual Alignment

Versal Adaptive SoC GTY and GTYP Transceivers Architecture Manual (AM002)

Document ID
Release Date
1.3 English

RXSLIDE is an alternative to automatic comma alignment for setting parallel data alignment. RXSLIDE is driven High for two RXUSRCLK cycles to shift the parallel data by one bit. RXSLIDE must be Low for at least 32 RXUSRCLK cycles before it can be used again.

The following figure shows the waveforms for manual alignment using RXSLIDE in RXSLIDE_MODE = PCS, before and after the data shift. When RXSLIDE_MODE = PCS is used, the number of bit shift positions when consecutive RXSLIDE pulses are issued is also determined by the comma alignment boundary set by ALIGN_COMMA_WORD, RX_DATA_WIDTH, and RX_INT_DATAWIDTH. For example, if the RX_DATA_WIDTH is 20 bits and ALIGN_COMMA_WORD is 1, after the ninth slide operation, the slide position returns to 0. For the same RX_DATA_WIDTH setting, for an ALIGN_COMMA_WORD setting of 2, the slide position returns to 0 after the 19th slide operation. Thus in RXSLIDE_MODE = PCS, a maximum of 40 bits of sliding is possible when RX_INT_DATAWIDTH = 1 (4-byte) and ALIGN_COMMA_WORD = 4.

Figure 1. Manual Data Alignment Using RXSLIDE for RX_DATA_WIDTH = 20 Bits and RXSLIDE_MODE = PCS

Note: Latency between the slide and the slide result at RXDATA depends on the number of active RX PCS blocks in the datapath.