
574
Chapter 31 External Bus
6.Burst Access Operation
6. Burst Access Operation
In the external bus interface, the operation that transfers successive data items in one access
sequence is called burst access. The normal access cycle (that is, not burst access) is called
single access. One access sequence starts with an assertion of AS and CSn and ends with ne-
gation of CSn. Multiple data items two or more units of data of the unit set for the area.
This section explains burst access operation.
■
Burst Access Operation
Figure 6-1
"Timing chart for burst access" shows the operation timing chart for (first wait cycle=1, inpage access
wait cycle=1, TYP3-0=0000
B
, AWR=1108
H
).
Figure 6-1 Timing Chart for Burst Access
•
In addition to more efficient use of access cycles when a sizable amount of data of asynchronous memory
such as page mode ROM and burst flash memory is read, burst cycles can also be used for reading from
normal asynchronous memory.
•
The access sequence when burst cycles are used can be divided into the following two types:
- First access cycle
The first access cycle is the start cycle for the burst access and operates in the same way as the normal single
access cycle.
- Page access cycle
The page access cycle is a cycle following the first access cycle in which both CSn and RD (read strobe) are
asserted. Wait cycles that are different from those set for a single cycle can be set. The page access cycle is
repeated while access remains in the address boundary determined by the burst length setting. When access
within the address boundary ends, burst access terminates and CSn is negated.
•
Setting of the W15-W12 bits of the AWR register enable the first 0-15 wait cycles to be inserted. At this point,
MCLK
AS
CSn
RD
WRn
D[31:0]
A[31:0]
BAA
First
cycle
wait
Inpage
access
wait
Inpage
access
wait
Inpage
access
wait
(LBA)
WRn
WR
Summary of Contents for FR Family FR60 Lite
Page 2: ...FUJITSU LIMITED ...
Page 3: ...FR60 32 BIT MICROCONTROLLER MB91460 Series User s Manual ...
Page 15: ...xi ...
Page 16: ...xii ...
Page 38: ...22 Chapter 2 MB91460 Rev A Rev B Overview 4 Block Diagram ...
Page 128: ...112 Chapter 4 CPU Architecture 9 Addressing ...
Page 153: ...137 Chapter 8 Device State Transition 3 State Transition Diagram ...
Page 154: ...138 Chapter 8 Device State Transition 3 State Transition Diagram ...
Page 169: ...153 Chapter 9 Reset 10 Caution ...
Page 170: ...154 Chapter 9 Reset 10 Caution ...
Page 180: ...164 Chapter 10 Standby 7 Q A ...
Page 182: ...166 Chapter 10 Standby 8 Caution ...
Page 199: ...183 Chapter 12 Instruction Cache 2 Main body structure Figure 2 3 I Cache Address Map ...
Page 200: ...184 Chapter 12 Instruction Cache 2 Main body structure Figure 2 4 I Cacheable Area ...
Page 222: ...206 Chapter 13 Clock Control 8 Caution ...
Page 232: ...216 Chapter 14 PLL Interface 7 Caution ...
Page 236: ...220 Chapter 15 CAN Clock Prescaler 3 Registers ...
Page 288: ...272 Chapter 19 Timebase Timer 8 Caution ...
Page 314: ...298 Chapter 22 Main Oscillation Stabilisation Timer 8 Caution ...
Page 326: ...310 Chapter 23 Sub Oscillation Stabilisation Timer 8 Caution ...
Page 348: ...332 Chapter 25 External Interrupt 8 Caution ...
Page 398: ...382 Chapter 26 DMA Controller 6 DMA External Interface ...
Page 402: ...386 Chapter 27 Delayed Interrupt 8 Caution ...
Page 412: ...396 Chapter 28 Bit Search 8 Caution ...
Page 521: ...505 Chapter 30 I O Ports 3 Port Register Settings ...
Page 522: ...506 Chapter 30 I O Ports 3 Port Register Settings ...
Page 574: ...558 Chapter 31 External Bus 4 Endian and Bus Access Byte Access ...
Page 628: ...612 Chapter 31 External Bus 13 Notes on Using the External Bus Interface ...
Page 706: ...690 Chapter 33 I2C Controller 4 Programming Flow Charts ...
Page 748: ...732 Chapter 34 CAN Controller 4 CAN Application ...
Page 762: ...746 Chapter 35 Free Run Timer 8 Caution ...
Page 790: ...774 Chapter 37 Output Compare 8 Caution ...
Page 838: ...822 Chapter 39 Programmable Pulse Generator 8 Caution ...
Page 850: ...834 Chapter 40 Pulse Frequency Modulator 4 PFM Operation and Setting ...
Page 886: ...870 Chapter 42 Sound Generator 3 Registers ...
Page 900: ...884 Chapter 43 Stepper Motor Controller 4 Caution ...
Page 939: ...923 Chapter 47 LCD Controller 3 Configuration Figure 3 2 Register List ...
Page 943: ...927 Chapter 47 LCD Controller 4 Registers Correspondence between VRAM and Common Segment Pins ...
Page 964: ...948 Chapter 48 Clock Monitor 8 Caution ...
Page 994: ...978 Chapter 51 Low Voltage Reset Interrupt 3 Registers ...
Page 998: ...982 Chapter 52 Regulator Control 3 Registers ...
Page 1008: ...992 Chapter 53 Fixed Mode Reset Vector BOOT ROM 5 Bootloader Update Strategy ...
Page 1024: ...1008 Chapter 54 Flash Memory 8 Caution ...
Page 1032: ...1016 Chapter 55 Flash Security 4 Register ...
Page 1034: ...1018 Chapter 56 Electrical Specification ...
Page 1035: ...FR60 MB91460 Series Hardware Manual European Microcontroller Design Centre Author MBo ...
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