![](http://datasheet.mmic.net.cn/30000/MC68EN360FE33_datasheet_2368935/MC68EN360FE33_298.png)
System Integration Module (SIM60)
6-54
MC68360 USER’S MANUAL
Figure 6-11. Minimum QUICC System Configuration
If a larger system is required, the only additional glue logic that may be needed is external
buffers (see
Figure 6-12). In this case, a boot EPROM and a flash EPROM are supported.
Also, two DRAM SIMMs are supported using RAS1 and RAS2.
Each of the eight memory banks may be used by an external master such as an
MC68EC040, MC68030, or even another QUICC. Whenever an external master accesses
DRAM, SRAM, or a peripheral within one of the regions of the memory banks, the memory
controller will control the access for that external master.
If DRAM is accessed by an external master, an external multiplexer must be provided. In
that case, the QUICC AMUX signal can be used to control the multiplexing. The DRAM con-
troller supports use by an MC68EC040 and another QUICC or MC68030-type device. In
such a case, the MC68EC040 and QUICC/MC68030-type device can access the DRAM in
different modes and at different rates. For instance, the MC68EC040 can access the DRAM
using two-clock bursts, while an external QUICC accesses the DRAM using page mode with
three-clock page hits, four-clock page normal, and five-clock page miss accesses. Thus, the
MC68EC040 access to DRAM is not slowed by the presence of other slower masters on the
system bus. In addition, the MC68EC040 is not slowed by the performance of the DRAM
accesses by the QUICC's internal bus masters (CPU32+, IDMAs, SDMAs, etc.) All
accesses may occur at different rates, with the MC68EC040 parameters being programmed
independently and the external QUICC/MC68030-type master being up to one wait state
QUICC
MC68360
CE (ENABLE)
OE (OUTPUT ENABLE)
WE (WRITE)
DATA
ADDRESS
8-BIT BOOT
EPROM
(FLASH OR REGULAR)
CS0
OE
WE0
DATA
ADDRESS
RAS
CAS3–CAS0
W (WRITE)
DATA
ADDRESS
PARITY
16- OR 32-BIT
DRAM SIMM
(OPTIONAL PARITY)
RAS1
CAS3–CAS0
R/W
PRTY3–PRTY0
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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