mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 1059

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

Development Capabilities and Interface
The status pins are divided into two groups—the instruction queue status and the history
buffer flush status.
NOTE: Unless the next clock has the VF pin set to 111, refer to Section 20.2.1.1 The Internal Hardware .
• VF[0:2]—Visible Instruction Queue Flushes Status
• VFLS[0:1]—Visible History Buffer Flushes Status
000
001
010
011
100
101
110
111
VF
Instruction queue status denotes the type of the last fetched instruction or the number
of instructions that were flushed from the instruction queue. These status pins are used
for both functions because queue flushes only happen in clocks with no fetch type
information to be reported, as shown in Table 20-1.
000 = None.
001 = 1 instruction was flushed from the instruction queue.
010 = 2 instructions were flushed from the instruction queue.
011 = 3 instructions were flushed from the instruction queue.
100 = 4 instructions were flushed from the instruction queue.
101 = 5 instructions were flushed from the instruction queue.
110 = Reserved.
111 = Special case. See Section 20.2.1.1 The Internal Hardware .
History buffer flushes status indicates the number of instructions that are flushed from
the history buffer on this clock.
00 = None.
01 = One instruction was flushed from the history buffer.
10 = Two instructions were flushed from the history buffer.
11 = Used for debug mode indication and must be ignored by the program trace
None
Sequential
Branch (direct or indirect) not taken
VSYNC was asserted/negated and therefore the next
instruction will be marked with the program trace cycle
attribute
Interrupt/exception taken, the target will be marked with
the program trace cycle attribute
Branch indirect taken, rfi , mtmsr , isync and in some
cases mtspr, the target will be marked with the program
trace cycle attribute
Branch direct taken
Branch (direct or indirect) not taken
external hardware. For details, refer to Section 20.4.2 Debug Mode .
INSTRUCTION TYPE
Table 20-1. VF Instruction Type Encoding
Freescale Semiconductor, Inc.
1
For More Information On This Product,
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
More instruction type information
Queue flush information
VF NEXT CLOCK WILL HOLD
2
MOTOROLA