BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
78
Section 4: System Control and Debug Unit
Document
1250_1125-UM100CB-R
The data trace consists of two 128 bit entries. The first contains bits [255:128] from the databus, the second
has bits [127:0].
63:60
A_DW
Encoded byte enables. Indicates any doublewords with valid bytes.
DW[n=3:0] = A_BE[8*n + 0] | A_BE[8*n + 1] | A_BE[8*n + 2] | A_BE[8*n + 3] |
A_BE[8*n + 4] | A_BE[8*n + 5] | A_BE[8*n + 6] | A_BE[8*n + 7]
If only one doubleword is set then the BYT field indicates the valid bytes, if more than one
doubleword is set then knowledge of the transaction will be needed. Other than uncached
accelerated writes, all CPU transactions will be within a single doubleword or of the full
cacheline.
65:64
A_L1CA
L1 cacheablility bits.
00: Cacheable non-coherent.
01: Cacheable coherent.
10: Uncacheable.
11: Uncacheable (accelerated, may have merged writes).
68:66
A_CMD
Address phase command bits
000: READ_SHD.
001: READ_EXC.
010: WRITE.
011: WRITE and INVALIDATE.
100: INVALIDATE.
101-110: Reserved
111: No command valid. (NOP)
103:69
A_AD[39:5]
Line address of the transaction on the bus.
113:104
A_ID[9:0]
This is the value of the address ID bits on the bus.
A_ID[9:6] - Requester ID.
A_ID[5:0] - Unique number within granted requester.
125:114
COUNT
This is the number of bus cycles between the last traced entry and this entry. This is a 12 bit
saturating counter. If two samples are captured on consecutive cycles the count will be zero.
The count is set to zero when the trace buffer is reset.
126
DTRIG
This bit is set when a sequence completing with Dsample caused this control entry to be
traced. The next 256 bits contains the data bits [255:0].
127
ATRIG
This bit is set when a sequence completing with Asample caused this control entry to be
traced.
Table 49: Trace Buffer Address/Control Bundle
(Cont.)
Bits
Field
Description