User Manual
BCM1250/BCM1125/BCM1125H
10/21/02
B r o a d c o m C o r p o r a t i o n
Document
1250_1125-UM100CB-R
Section 4: System Control and Debug Unit
Page
75
The special event selection sequence 16'hFFFF written in one of the trace sequence registers will cause all
bus cycles to be selected. There are several possible actions depending on which of bits 18,19,23 and 24 are
set:
•
Asample (bit 18): An address/control sample is taken every time the address bus is used.
•
Dsample (bit 19): An address/control and data sample is taken every time the data bus is used.
•
Alld_a (bit 23): An address/control sample is taken every time the data bus is used.
•
Asample and Alld_a (bits 18 and 23): An address/control sample is taken every time either address bus or
data bus is used.
•
Asample and Dsample (bits 18 and 19): An address/control sample is taken every time the bus is used,
with data also being captured if the data bus is used.
•
All_a (bit 24): An address/control sample is taken on every bus cycle.
Using these sequences a trace of the entire active bus can be taken. To avoid the count of cycles between
samples overflowing, the forceCnt bit can be set in the
trace_cfg
register to force an address/control sample
to be taken just before overflow. The sample collected when a section of the bus is not used is
UNPREDICTABLE. The Avalid and Dvalid bits in the address/control bundle are used to indicate which bits in
the bundle are valid. The All_a flag can be used in profiling to monitor the blocking and interrupt signals on
every cycle.
17:16
Function
2‘b0
These bits set the function that should be performed when the sequence completes.
00: Nop. No function is performed.
01: Start. The trace collection is started.
10: Stop. Trace collection is stopped.
11: Freeze. The trace buffer is frozen.
18
Asample
1‘b0
If this bit is set then an address trace is taken when the sequence completes, if
Dsample is set this bit is ignored, unless all the select fields are 4’hF.
If the select fields are all 4’hF and Asample is set then an address trace is taken every
time the address bus is granted (i.e. NOP cycles are included).
19
Dsample
1‘b0
If this bit is set then an address and a data trace is taken when the sequence
completes.
If the select fields are all 4’hF and Dsample is set then an address and a data trace
is taken every time the data bus is granted (i.e. NOP cycles are included).
20
DebugPin
1‘b0
If this bit is set then the external debug pin is pulled low when the sequence
completes.
21
DebugCPU
1‘b0
If this bit is set then debug interrupts will be sent to both CPUs when the sequence
completes.
22
ClearUse
1‘b0
If this bit is set then the buffer use counter is cleared, so the buffer full condition will
not be raised until this buffer entry and 255 others have been used.
23
Alld_a
1‘b0
If the select fields are all 4'hF and this bit is set then an address/control sample is
taken whenever the data bus is used.
24
All_a
1‘b0
If the select fields are all 4'hF and this bit is set then an address/control sample is
taken on every bus cycle.
Table 47: Trace Sequence Control Registers
(Cont.)
trace_sequence_0 -
00_1002_0A40
trace_sequence_1 -
00_1002_0A48
trace_sequence_2 -
00_1002_0A50
trace_sequence_3 -
00_1002_0A58
trace_sequence_4 -
00_1002_0A80
trace_sequence_5 -
00_1002_0A88
trace_sequence_6 -
00_1002_0A90
trace_sequence_7 -
00_1002_0A98
Bits
Field
Default
Description