MPC555
/
MPC556
SIGNAL DESCRIPTIONS
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
2-19
Bus Busy –
Indicates that the master is using the bus. This pin is an active negate
signal and may need an external pull-up resistor to ensure proper operation and signal
timing specifications.
Visible Instruction Queue Flush Status –
This output line together with VF0 and VF1
is output by the chip when a program instructions flow tracking is required by the user.
VF report the number of instructions flushed from the instruction queue in the internal
core.
Instruction Watchpoint 3 –
This output line reports the detection of an instruction
watchpoint in the program flow executed by the internal core.
2.3.1.30 IWP[0:1]/VFLS[0:1]
Pin Name:
iwp0_vfls0 - iwp1_vfls1 (2 pins)
Instruction Watchpoint –
These output lines report the detection of an instruction
watchpoint in the program flow executed by the RCPU.
Visible History Buffer Flush Status –
These signals are output by the chip to enable
program instruction flow tracking. They report the number of instructions flushed from
the history buffer in the RCPU. See
SECTION 21 DEVELOPMENT SUPPORT
for de-
tails.
2.3.1.31 TMS
Pin Name
: tms
Test Mode Select –
This input controls test mode operations for on-board test logic
(JTAG).
2.3.1.32 TDI/DSDI
Pin Name
: tdi_dsdi
Test Data In –
This input is used for serial test instructions and test data for on-board
test logic (JTAG).
Development Serial Data Input –
This input line is the data in for the debug port in-
terface. See
SECTION 21 DEVELOPMENT SUPPORT
for details.
2.3.1.33 TCK/DSCK
Pin Name
: tck_dsck
Test Clock –
This input provides a clock for on-board test logic (JTAG).
Development Serial Clock –
This input line is the clock for the debug port interface.
See
SECTION 21 DEVELOPMENT SUPPORT
for details.
2.3.1.34 TDO/DSDO
Pin Name
: tdo_dsdo
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..