Motorola MVME187 User Manual
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Board Level Hardware Description
2
Data Bus Structure
The local data bus on theMVME187 is a 32-bit synchronous bus
based on the MC68040 bus, and supports burst transfers and
snooping.
based on the MC68040 bus, and supports burst transfers and
snooping.
Local Bus Arbitration
The various local bus master and slave devices use the local bus to
communicate.
communicate.
The local bus is arbitrated by priority type arbiter and the priority
of the local bus masters from highest to lowest is:
of the local bus masters from highest to lowest is:
1. 82596CA LAN (highest)
2. CD2401 serial (through the PCCchip2)
3. 53C710 SCSI
4. VMEbus
5. MPU (lowest)
In general, any master can access any slave; however, not all
combinations pass the Òcommon sense test.Ó Refer to the Single
Board Computers Programmer's Reference Guide and to the user's
guide for each device to determine its port size, data bus
connection, and any restrictions that apply when accessing the
device.
combinations pass the Òcommon sense test.Ó Refer to the Single
Board Computers Programmer's Reference Guide and to the user's
guide for each device to determine its port size, data bus
connection, and any restrictions that apply when accessing the
device.
M88000 MPU
The MVME187 is based on the M88000 family and uses one
MC88100 MPU and two MC88200 or MC88204 CMMUs.
MC88100 MPU and two MC88200 or MC88204 CMMUs.
One CMMU is used for the data cache and one is used for the
instruction cache.
instruction cache.
More information is available in the MC88100 and MC88200 user's
manuals and the MC88204 data sheet.
manuals and the MC88204 data sheet.