MOTOROLA
Chapter 16. Memory Controller
16-29
Part IV. Hardware Interface
Figure 16-30. Asynchronous External Master, GPCM-Handled Memory Access
Timing (TRLX = 0)
When an external asynchronous master performs accesses a memory device via the GPCM
in the memory controller, ORx[CSNT] has no effect.
For a comprehensive discussion of external master interfacing, see Section 16.8, ÒExternal
Master Support.Ó
16.5.4 Special Case: Bursting with External Transfer Acknowledge:
The memory controller supports bursting to and from an external slave that supplies its own
TA termination signal in the following special case:
The GPCM is the subsystem of the memory controller that supports provision of chip-select
signals (CSx) for slaves that provide their TA signal external to the MPC8560 (ORx[SETA]
= 1). However, the GPCM keeps its chip-select asserted only until the Þrst TA is sampled.
The GPCM cannot be used to burst to an external device the requires that the chip-select
signal remain asserted throughout a burst transaction. However, if the device requires only
that the chip-select be asserted up to the Þrst data beat of the burst, it is possible to burst to
this device. The user can program ORx[SETA] = 1 and ORx[BIH] = 0 to enable this
operation. This is the only case in which it is valid to program ORx[BIH] = 0 for a
chip-select controlled by the GPCM.
During a burst cycle, the user sees the chip-select assertion follow the same pattern as for a
single-beat cycle. However, BI remains negated, and the burst continues for the following
data beats after the negation of chip-select following TA for the Þrst data beat.
Clock
Address
AS
TA
CS
WE
OE
Data
Содержание MPC860 PowerQUICC
Страница 3: ...MPC860UM AD 07 98 REV 1 MPC860 PowerQUICC ª UserÕs Manual ...
Страница 36: ...xxxvi MPC860 PowerQUICC UserÕs Manual MOTOROLA CONTENTS Paragraph Number Title Page Number ...
Страница 78: ...I iv MPC860 PowerQUICC UserÕs Manual MOTOROLA Part I Overview ...
Страница 88: ...1 10 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part I Overview ...
Страница 114: ...3 16 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part I Overview ...
Страница 226: ...8 32 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part II PowerPC Microprocessor Module ...
Страница 262: ...9 36 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part II PowerPC Microprocessor Module ...
Страница 274: ...III iv MPC860 PowerQUICC UserÕs Manual MOTOROLA Part III Configuration ...
Страница 320: ...12 12 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part III Configuration ...
Страница 325: ...MOTOROLA Part IV Hardware Interface IV v Part IV Hardware Interface ...
Страница 326: ...IV vi MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Страница 352: ...13 26 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Страница 394: ...14 42 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Страница 426: ...15 32 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Страница 530: ...17 26 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Страница 632: ...21 44 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 660: ...22 28 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 708: ...24 24 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 748: ...27 20 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 846: ...31 20 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 914: ...35 12 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 948: ...36 34 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Страница 998: ...37 48 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part VI Debug and Test ...
Страница 1016: ...A 10 MPC860 PowerQUICC UserÕs Manual MOTOROLA Appendixes ...
Страница 1024: ...B 8 MPC860 PowerQUICC UserÕs Manual MOTOROLA Appendixes ...
Страница 1030: ...C 6 MPC860 PowerQUICC UserÕs Manual MOTOROLA Appendixes ...
Страница 1086: ...Glossary 12 MPC860 PowerQUICC UserÕs Manual MOTOROLA ...
Страница 1106: ......