Intel® Quartus® Prime Standard Edition User Guide: Debug Tools

ID 683552
Date 9/24/2018
Public
Document Table of Contents

2.8.3. SLD Service

The SLD Service shifts values into the instruction and data registers of SLD nodes and captures the previous value. When interacting with a SLD node, start by acquiring exclusive access to the node on an opened service.

SLD Service

set timeout_in_ms 1000
set lock_failed [sld_lock $sld_service_path $timeout_in_ms]

This code attempts to lock the selected SLD node. If it is already locked, sld_lock waits for the specified timeout. Confirm the procedure returns non-zero before proceeding. Set the instruction register and capture the previous one:

if {$lock_failed} {
    return
}
set instr 7
set delay_us 1000
set capture [sld_access_ir $sld_service_path $instr $delay_us]

The 1000 microsecond delay guarantees that the following SLD command executes least 1000 microseconds later. Data register access works the same way.

set data_bit_length 32
set delay_us 1000
set data_bytes [list 0xEF 0xBE 0xAD 0xDE]
set capture [sld_access_dr $sld_service_path $data_bit_length $delay_us \
$data_bytes]

Shift count is specified in bits, but the data content is specified as a list of bytes. The capture return value is also a list of bytes. Always unlock the SLD node once finished with the SLD service.

sld_unlock $sld_service_path