VS1005g Datasheet
11 VS1005 DEBUGGER
11 VS1005 Debugger
VS1005 has a hardware debugger which uses common Joint Test Action Group (JTAG) inter-
face. The JTAG pins are in hardware debug mode when the dbgmode pin is pulled high. This
enables the JTAG pins to access Test Acess Port (TAP) controller and swithes clocks to debug
mode.
Vs1005 Hardware Debuger Pins
Name
Package pin Description
tms
tdi
31 Test mode select
32 Test data in
tdo
tck
33 Test data out
34 Test clock
dbgreq
dbgmode
35 Debug interrupt
61 JTAG debug mode enable
Debug functions are controlled with JTAG DR (data) and IR (instruction) registers which can be
written and read in predefined JTAG states. JTAG state machine is shown in Figure 21.
Figure 21: JTAG state machine.
TAP function is selected by writing a special 4-bit instruction to IR register. Additionally to debug
functions, some common JTAG functions are supported.
Version: 0.2, 2012-03-16
100
ETC [ ETC ]
