Signal Descriptions
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
2-29
2.5.1
JTAG Mode Selection
The MPC561/MPC563 has five JTAG signals. The test data input (TDI) and test data output (TDO) scan
ports are used to scan instructions as well as data into the various scan registers for JTAG operations. The
scan operation is controlled by the test access port (TAP) controller, which in turn is controlled by the test
mode select (TMS) input sequence. The scan data is latched at the rising edge of the test clock (TCK).
On the MPC561/MPC563, JTAG is used for boundary scan only. There is no access to internal
MPC561/MPC563 circuitry. When JTAG mode is enabled, the READI module will be held inactive. See
for JTAG mode selection.
JTAG is entered by the following sequence of events:
•
Assert PORESET/TRST to reset the JTAG TAP controller
•
Hold JCOMP/RSTI high prior to PORESET/TRST negation and keep high as long as JTAG mode
is required
(The READI module will be held inactive since only one of the multiplexed functions JCOMP and
RSTI can be asserted at the negation of PORESET/TRST).
JTAG mode is exited by:
•
Drive JCOMP/RSTI low.
NOTE
PORESET/TRST and analog signals ANx, EXTAL, XTAL, and
TDI/TDO/TMS/TCK are not in the JTAG scan path.
Table 2-13. MPC561/MPC563 Mode Selection Options
Signal
State
When Sampled
Affect
BDM Mode
DSCK
High
SRESET negation
BDM mode enabled
Low
SRESET negation
BDM mode disabled
DSDI
High
8 clocks after SRESET
Synchronous mode
Low
8 clocks after SRESET
Asynchronous mode
Nexus Configuration
EVTI
High
RSTI negation
READI module Disabled
Low
RSTI negation
READI module Enabled
MDI0
High
EVTI negation
Full Port mode
Low
EVTI negation
Reduced port mode
JTAG Selection
JCOMP
Low
PORESET
Nexus or BDM allowed
High
PORESET
JTAG Mode Selected
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...