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50 www.xilinx.com SPI-4.2 v8.5 Getting Started Guide

UG154 March 24, 2008

Appendix B: Verilog Details

The send_user_data procedure is used to transmit a burst of data. The presence of a

SOP control word (before the burst of data) and an EOP control word (following the data

burst), can be specified. The EOPS (bits 14:13 of the control word following the burst) are

automatically calculated from the number of bytes sent. ERR has a higher priority than

EOP; if EOP and ERR are both ‘1’, the EOPs for the burst is an EOP abort = ‘01.’

The send_idles procedure is used to send idle control words.

The send_training procedure is used to send training patterns.

The sop_spacing procedure is used to send erred data by sending two SOPs in less than

eight cycles. This function limits the number of cycles between the two SOPs to less than

seven. This ensures that a SOP spacing error occurs.

Table B - 2 : send_user_data (SOP, EOP, Err, Addr, bytes) Inputs

Name Range Description

SOP 0 or 1 Defines if the packet should begin with an SOP.

EOP 0 or 1 Defines if the packet should be terminated with

an EOP.

ERR 0 or 1 Defines if the packet should be terminated with

an EOP abort.

ADDR 0 to 255 Channel on which the packet should be sent.

BYTES 1 to 255 Number of bytes to send on the selected channel.

Table B - 3 : send_idles (cycles) Inputs

Name Range Description

CYCLES 0 to 511 Number of idle control words to send on RDat.

Table B - 4 : send_training (patterns) Inputs

Name Range Description

PATTERNS 0 to 255 Number of training patterns to send.

Table B - 5 : sop_spacing (Bytes1, Err1, Addr1, EOP2, Err2, Addr2, Bytes2,

num_cycles) Inputs

Name Range Description

BYTES1 0 to 10 The number of bytes to send in the first burst. This

is limited to 10 bytes to ensure SOP spacing is

violated.

ERR1 0 or 1 Defines if the first packet should be terminated with

an EOP abort. If set to 0 the EOPs will be calculated

from BYTES1.

ADDR1 0 to 255 Channel on which the first packet should be sent.

EOP2 0 or 1 Defines if the second packet should be terminated

with an EOP.