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 3: System Overview
Page
9
S e c t i o n 3 : S y s t e m O v e r v i e w
I
NTRODUCTION
A logical block diagram of the BCM1250 and BCM1125/H family is shown in
. This figure does not
exactly match the implementation details, but it gives a more useful model for programmers and system
designers to use. The system is based around the ZBbus, a high speed split-transaction multiprocessor bus.
It connects the CPU(s), the level 2 cache (L2), the memory controller, two I/O bridges and the System Control
and Debug unit (SCD).
Figure 5: Logical Block Diagram of BCM1250 and BCM1125/H
System Control & Debug
Performance
Data
L1
Inst.
L1
L2
DDR SDRAM
Ch1
Data
L1
Inst.
L1
Monitor
Interrupt
Mappers
Timers
Generic
Data Mover
Bus Trace
Controller
Bus Error
Log/Counters
Address Trap
Trace
Buffer
I/O
Bridge 0
I/O
Bridge 1
PCI
Host
Bridge
HT
Host
Bridge
PCI
Bus
HT
Fabric
DMA
MAC0
DMA
MAC1
DMA
Serial0
DUART
A
B
DMA
Serial1
SMBus
Master
Generic
Bus
Bridge
Generic
Bus
SMB0 SMB1
G/MII
G/MII
Serial0
Serial1
Address/Response
Data
JTAG
ZBbus
Memory
Controller
PCMCIA
Control
& GPIO
PCMCIA
&
GPIO
SB-1
CPU 0
SB-1
CPU 1
DMA
MAC2
G/MII
HT configured
as if bridge from PCI
Ch0
Only in BCM1250
Only in
BCM1250
BCM1250, BCM1125H PCI & HT
BCM1125 Only PCI
Only in
BCM1250