User manual

Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 715
UG585 (v1.11) September 27, 2016
Chapter 27: JTAG and DAP Subsystem
27.4 Programming Model
27.4.1 Use Case I: Software Debug with Trace Port Enabled
This is the normal debug case for most applications. Figure 27-4 shows ARM tool chain solution. It is
also possible to replace ARM Real View ICE with a Xilinx or Lauterbach debug tool. In this case, there
is no PL programming required and the user is able to start on software debug as soon as chip power
is on. In this use case, the DAP is active to support software debug needs but the TAP is put into
bypass mode. Trace port is also enabled through the MIO pin. Although bandwidth might be limited
due to limited MIO availability in some cases, the user could enable a trace dump without depending
on PL configuration in this configuration. The major challenge for most users is to allocate MIO pins
for the Trace port.
27.4.2 Use Case II: PS and PL Debug with Trace Port Enabled
The second use case shows how to enable PS software and PL hardware at the same time with two
separate debug tools. The tool connected to the Xilinx TAP is typically a Xilinx debug tool. The tools
connected to the PS DAP could be Xilinx or any third-party debug tools from ARM or Lauterbach.
To support this mode, PL configuration is required to bring the DAP JTAG signals to the PL SelectIOs.
Figure 27-5 shows trace port access through the PL SelectIO, but the user could use the MIO trace
port as in the previous use case if there is way to manage to fit the trace port into the limited MIO
pin multiplexing. Trace port access through SelectIO could support up to 32-bit trace data and gives
users enough trace port throughput to address most debug need. As with the JTAG DAP access, the
X-Ref Target - Figure 27-4
Figure 27-4: User Case I: Software Debug with Trace Port Enabled
DAP TAP
TPIU
JTAG
SS
SS
SRST
PS
PL
ARM
DStream
ARM Real
View ICE
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