
Nexus Development Interface (NDI)
PXN20 Microcontroller Reference Manual, Rev. 1
36-46
Freescale Semiconductor
e200z6 Direct Branch Message Instructions (Power Architecture Book E)
shows the types of instructions that cause direct branch messages or toggle a bit in the
instruction history buffer to be messaged out in a resource full message or branch history message.
BTM Using Branch History Messages
Traditional BTM messaging can accurately track the number of sequential instructions between branches,
but cannot accurately indicate which instructions were conditionally executed, and which were not.
Branch history messaging solves this problem by providing a predicated instruction history field in each
indirect branch message. Each bit in the history represents a predicated instruction or direct branch. A
value of one (1) indicates the conditional instruction was executed or the direct branch was taken. A value
of zero (0) indicates the conditional instruction was not executed or the direct branch was not taken.
Certain instructions (
evsel
) generate a pair of predicate bits that are both reported as consecutive bits in the
history field.
Branch history messages solve predicated instruction tracking and save bandwidth since only indirect
branches cause messages to be queued.
BTM Using Traditional Program Trace Messages
Based on the PTM bit in the DC register (DC[PTM]), program tracing can utilize either branch history
messages (DC[PTM] = 1) or traditional direct/indirect branch messages (DC[PTM] = 0).
Branch history saves bandwidth and keeps consistency between methods of program trace, yet may lose
temporal order between BTM messages and other types of messages. Since direct branches are not
messaged, but are instead included in the history field of the indirect branch history message, other types
of messages may enter the FIFO between branch history messages. The development tool cannot
determine the ordering of “events” that occurred with respect to direct branches simply by the order in
which messages are sent out.
Table 36-31. Indirect Branch Message Sources
Source of Indirect Branch Message
Instructions
Taken branch relative to a register value
bcctr, bcctrl, bclr, bclrl, se_bctr,
se_bctrl, se_blr, se_blrl
System Call / Trap exceptions taken
sc, tw, twi, se_sc
Return from interrupts / exceptions
rfi, rfci, rfdi, se_rfi, se_rfci,
se_rfdi
Table 36-32. Direct Branch Message Sources
Source of Direct Branch Message
Instructions
Taken direct branch instructions
b, ba, bl, bla, bc, bca, bcl, bcla,
se_b. se_bc, se_bl, e_b, e_bc,
e_bl, e_bcl,
Instruction Synchronize
isync, se_isync
Содержание PXN2020
Страница 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Страница 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Страница 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Страница 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Страница 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Страница 162: ...Clocks Reset and Power CRP PXN20 Microcontroller Reference Manual Rev 1 6 30 Freescale Semiconductor...
Страница 182: ...Frequency Modulated Phase Locked Loop FMPLL PXN20 Microcontroller Reference Manual Rev 1 7 20 Freescale Semiconductor...
Страница 268: ...Boot Assist Module BAM PXN20 Microcontroller Reference Manual Rev 1 9 14 Freescale Semiconductor...
Страница 318: ...Interrupts and Interrupt Controller INTC PXN20 Microcontroller Reference Manual Rev 1 10 50 Freescale Semiconductor...
Страница 326: ...General Purpose Static RAM SRAM PXN20 Microcontroller Reference Manual Rev 1 11 8 Freescale Semiconductor...
Страница 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Страница 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Страница 460: ...Memory Protection Unit MPU PXN20 Microcontroller Reference Manual Rev 1 18 20 Freescale Semiconductor...
Страница 478: ...Error Correction Status Module ECSM PXN20 Microcontroller Reference Manual Rev 1 19 18 Freescale Semiconductor...
Страница 488: ...Software Watchdog Timer SWT PXN20 Microcontroller Reference Manual Rev 1 20 10 Freescale Semiconductor...
Страница 494: ...System Timer Module STM PXN20 Microcontroller Reference Manual Rev 1 21 6 Freescale Semiconductor...
Страница 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Страница 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Страница 926: ...Controller Area Network FlexCAN PXN20 Microcontroller Reference Manual Rev 1 29 42 Freescale Semiconductor...
Страница 990: ...Deserial Serial Peripheral Interface DSPI PXN20 Microcontroller Reference Manual Rev 1 30 64 Freescale Semiconductor...
Страница 1044: ...Enhanced Serial Communication Interface eSCI PXN20 Microcontroller Reference Manual Rev 1 31 54 Freescale Semiconductor...
Страница 1080: ...Cross Triggering Unit CTU PXN20 Microcontroller Reference Manual Rev 1 33 12 Freescale Semiconductor...
Страница 1134: ...Analog to Digital Converter ADC PXN20 Microcontroller Reference Manual Rev 1 34 54 Freescale Semiconductor...
Страница 1150: ...IEEE 1149 1 Test Access Port Controller JTAGC PXN20 Microcontroller Reference Manual Rev 1 35 16 Freescale Semiconductor...
Страница 1257: ...Nexus Development Interface NDI PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 36 107...
Страница 1258: ...Nexus Development Interface NDI PXN20 Microcontroller Reference Manual Rev 1 36 108 Freescale Semiconductor...
Страница 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...