HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 314
![no-image](/images/no-image-200.jpg)
HD6417615
Manufacturer Part Number
HD6417615
Description
Hardware Manual
Manufacturer
Hitachi Semiconductor
Datasheet
1.HD6417615.pdf
(873 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
HD6417615ARBPV
Manufacturer:
Renesas Electronics America
Quantity:
10 000
Company:
Part Number:
HD6417615ARF
Manufacturer:
HIT
Quantity:
5 510
Company:
Part Number:
HD6417615ARF
Manufacturer:
ABB
Quantity:
5 510
Part Number:
HD6417615ARF
Manufacturer:
RENESAS/瑞萨
Quantity:
20 000
Company:
Part Number:
HD6417615ARFV
Manufacturer:
HITACHI
Quantity:
239
Company:
Part Number:
HD6417615ARFV
Manufacturer:
Renesas Electronics America
Quantity:
10 000
Part Number:
HD6417615ARFV
Manufacturer:
RENESAS/瑞萨
Quantity:
20 000
- Current page: 314 of 873
- Download datasheet (3Mb)
7.5.4
Single Reads
When a cache area is accessed and there is a cache miss, the cache fill cycle is performed in 16-
byte units. This means that all the data read in the burst read is valid. On the other hand, when a
cache-through area is accessed the required data is a maximum length of 32 bits, and the
remaining 12 bytes are wasted. The same kind of wasted data access is produced when
synchronous DRAM is specified as the source in a DMA transfer by the DMAC and the transfer
unit is other than 16 bytes. Figure 7.21 (a) and (b) show the timings of a single address read.
Because the synchronous DRAM is set to the burst read mode, the read data output continues after
the required data is received. To avoid data conflict, an empty read cycle is performed from Td2 to
Td4 after the required data is read in Td1 and the device waits for the end of synchronous DRAM
operation.
When the data width is 16 bits, the number of burst transfers during a read is 8. Data is fetched in
cache-through and other DMA read cycles only in the Td1 and Td2 cycles (of the 8 cycles from
Td1 to Td8) for longword accesses, and only in the Td1 cycle for word or byte accesses.
Empty cycles tend to increase the memory access time, lower the program execution speed, and
lower the DMA transfer speed, so it is important to avoid accessing unnecessary cache-through
areas and to use data structures that enable 16-byte unit transfers by placing data on 16-byte
boundaries when performing DMA transfers that specify synchronous DRAM as the source.
297
Related parts for HD6417615
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![HM628128LFP-10](/images/manufacturer_photos/0/3/301/hitachi_tmb.jpg)
Part Number:
Description:
HM628128LFP-10Hitachi Semiconductor [131072-word x 8-bit High Speed CMOS Static RAM]
Manufacturer:
HITACHI
Datasheet:
![2SK1070](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel Junction FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK1151](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK1215](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK1697](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK1772](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK217](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel Junction FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK2315](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK2569](/images/no-image3.png)
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK2685](/images/no-image3.png)
Part Number:
Description:
GaAs HEMT
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK2926](/images/no-image3.png)
Part Number:
Description:
Silicon N Channel MOS FET High Speed Power Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK2980](/images/no-image3.png)
Part Number:
Description:
Silicon N Channel MOS FET High Speed Power Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK3000](/images/no-image3.png)
Part Number:
Description:
Silicon N Channel MOS FET Low Frequency Power Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK3289](/images/no-image3.png)
Part Number:
Description:
Silicon N Channel MOS FET High Speed Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
![2SK3378](/images/no-image3.png)
Part Number:
Description:
Silicon N Channel MOS FET High Speed Switching
Manufacturer:
Hitachi Semiconductor
Datasheet: