
Nexus Development Interface (NDI)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
36-93
of one (1). This bit acts as a stop bit so that the development tools can determine which bit is the end of
the history information. The pre-loaded bit itself is not part of the history, but is transmitted with the
packet.
A value of one (1) is shifted into the history buffer on a taken branch (condition or unconditional) and on
any instruction whose predicate condition executed as true. A value of zero (0) is shifted into the history
buffer on any instruction whose predicate condition executed as false as well as on branches not taken.
This includes indirect as well as direct branches not taken. For the
evsel
instruction, two bits are shifted
in, corresponding to the low element (shifted in first) and the high element (shifted in second) conditions.
Sequential Instruction Count (I-CNT)
The I-CNT packet, is present in all BTM messages. For traditional branch messages, I-CNT represents the
number of sequential instructions, or non-taken branches in between direct/indirect branch messages.
For branch history messages, I-CNT represents the number of instructions executed since the last
taken/non-taken direct branch, last taken indirect branch or exception. Not taken indirect branches are
considered sequential instructions and cause the instruction count to increment. I-CNT also represents the
number of instructions executed since the last predicate instruction.
The sequential instruction counter overflows when its value reaches 255. The next BTM message is
converted to a synchronization type message.
Program Trace Queueing
implements a message queue. Messages that enter the queue are transmitted via the auxiliary pins
in the order in which they are queued.
NOTE
If multiple trace messages need to be queued at the same time, Watchpoint
Messages have the highest priority (WPM
OTM
BTM
DTM).
36.7.9.3.4
Program Trace Timing Diagrams
Figure 36-72. Program Trace (MDO = 12)—Indirect Branch Message (Traditional)
MCKO
MSEO[1:0]
TCODE = 4
Source Processor = 0b0000
Number of Sequence Instructions = 128
Relative Address = 0xA5
01
11
00
MDO[11:0]
0000 0010 0000
0000 1010 0101
0000 0000 0100
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...