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
136
Section 6: DRAM
Document
1250_1125-UM100CB-R
60
ecc_disable
1’b0
ECC disable. If this bit is set ECC checking will not be performed and data will never
be reported to have an error.
61
berr_disable
1’b0
Bus error disable. This bit sets the behavior when a read is done to an address that
does not match any chip select range.
0: Generate a bus error data return
1: Generate a valid data return containing UNPREDICTABLE data.
On the BCM1250 if this bit is set in either channel, bus errors will be disabled for all
reads.
62
force_seq
1’b0
Force Sequential. If this bit is set requests will be issued to memory in the same
order their A-phase happens on the ZBbus.
63
debug
1’b0
This bit enables debug functions in the controller. It should be clear during normal
operation. The action if the bit is set is different for the two channels:
Channel 0: Reserved
Channel 1: Broadcom Use Only ( was Enable ZBbus monitoring mode).
Table 73: Memory Channel Configuration Register on BCM1125/H
mc_config_0 -
00_1005_1100
mc_config_1 -
00_1005_2100
Bits
Name
Default
Description
15:0
reserved
16’b0
Reserved
19:16
bank0_map
4’h0
mc_config_1
: Value of physical address bits [31:28] that should map to 0 (1st
256MB block)
mc_config_0
: Reserved.
23:20
bank1_map
4’h8
mc_config_1
: Value of physical address bits [31:28] that should map to 1 (2nd
256MB block)
mc_config_0
: Reserved.
27:24
bank2_map
4’h9
mc_config_1
: Value of physical address bits [31:28] that should map to 2 (3rd
256MB block)
mc_config_0
: Reserved.
31:28
bank3_map
4’hC
mc_config_1
: Value of physical address bits [31:28] that should map to 3 (4th
256MB block)
mc_config_0
: Reserved.
39:32
probe_mode
8’b0
mc_config_1
: Reserved, Broadcom Use Only. Setting these bits to any value other
than zero will result in UNDEFINED behavior and can cause the ECC lines to be
continually driven regardless of the direction of the data transfer.
mc_config_0
: Reserved.
43:40
iob1_qsize
4’ha
These fields are used to set the range of queue entries reserved for use by I/O
Bridge 1. The two channel configuration registers set a range to give hysteresis to
the blocking.
mc_config_0
: Queue size to start blocking agents other than IOB1.
mc_config_1
: Queue size to stop blocking agents other than IOB1.
47:44
age_limit
4’h8
mc_config_1
: Maximum number of younger reads that can pass a read in the
request queue, before the read is serviced. See
.
mc_config_0
: Reserved.
51:48
wr_limit
4’h5
mc_config_1
: Maximum number of writes in a burst to memory before reads will
be serviced. See
Section: “Memory Controller Architecture” on page 104
.
mc_config_0
: Reserved.
Table 72: Memory Channel Configuration Register on BCM1250
(Cont.)
mc_config_0 -
00_1005_1100
mc_config_1 -
00_1005_2100
Bits
Name
Default
Description