Memory Controller
MPC561/MPC563 Reference Manual, Rev. 1.2
10-28
Freescale Semiconductor
10.8
Memory Controller External Master Support
The memory controller in the MPC561/MPC563 supports accesses initiated by both internal and external
bus masters to external memories. If the address of any master is mapped within the internal
MPC561/MPC563 address space, the access will be directed to the internal device, and will be ignored by
the memory controller. If the address is not mapped internally, but rather mapped to one of the memory
controller regions, the memory controller will provide the appropriate chip select and strobes as
programmed in the corresponding region (see
Section 6.2.2.1.3, “External Master Control Register
”).
The MPC561/MPC563 supports only synchronous external bus masters. This means that the external
master works with CLKOUT and implements the MPC561/MPC563 bus protocol to access a slave device.
A synchronous master initiates a transfer by asserting TS. The ADDR[0:31] signals must be stable from
the rising edge of CLKOUT during which TS is sampled, until the last TA acknowledges the transfer. Since
the external master works synchronously with the MPC561/MPC563, only setup and hold times around
the rising edge of CLKOUT are important. Once the TS is detected/asserted, the memory controller
compares the address with each one of its defined valid banks to find a possible match. But, since the
external address space is shorter than the internal space, the actual address that is used for comparing
against the memory controller regions is in the format of: {00000000, bits [8:16] of the external address}.
In the case where a match is found, the controls to the memory devices are generated and the transfer
acknowledge indication (TA) is supplied to the master.
Table 10-5. Boot Bank Fields Values After Hard Reset
Field
Value (Binary)
PS
RCW[4:5] BPS
SST
0
BL
0
WP
0
SETA
0
BI
0b1
V
CS0 = ID3
CS3 = ID20 & ID31
AM[0:16]
0 0000 0000 0000 0000
ATM[0:2]
000
CSNT
0
ACS[0:1]
00
EHTR
0
SCY[0:3]
0b1111
BSCY[0:2]
0b011
TRLX
0
Summary of Contents for MPC561
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Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
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Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...