Section 11 Local Bus State Controller (LBSC)
Rev.1.00 Dec. 13, 2005 Page 352 of 1286
REJ09B0158-0100
11.5 Operation
11.5.1
Endian/Access Size and Data Alignment
This LSI supports both big-endian mode, in which the upper byte in a string of byte data is at
address 0, and little-endian mode, in which the lower byte in a string of byte data is at address 0.
The mode is specified by the external pin (MODE5 pin) at a power-on reset through the RESET
pin. At a power-on reset by
PRESET
, big-endian mode is specified when the MODE5 pin is low,
and little-endian mode is specified when the MODE5 pin is high.
A data bus width of 8, 16, or 32 bits can be selected for the normal memory interface, and one of 8
or 16 bits can be selected for the PCMCIA interface. Data alignment is carried out according to the
data bus width and endian mode of each device. Accordingly, when the data bus width is smaller
than the access size, multiple bus cycles are automatically generated to reach the access size. In
this case, access is performed by incrementing the addresses corresponding to the bus width. For
example, when a longword access is performed at the area with an 8-bit width in the SRAM
interface, each address is incremented one by one, and then access is performed four times. In the
32-byte transfer, a total of 32-byte data is continuously transferred according to the set bus width.
The first access is performed on the data for which there was an access request, and the remaining
accesses are performed in wraparound method according to the set bus width. The bus is not
released during these transfers. In this LSI, data alignment and data length conversion between
different interfaces is performed automatically.
When an 8- or 16-byte transfer is requested, the LBSC executes the transfer in two or four separate
4-byte accesses.
The relationship between the endian mode, device data length, and access unit are shown in tables
11.9 to 11.14.
Содержание SH7780 Series
Страница 2: ...Rev 1 00 Dec 13 2005 Page ii of l ...
Страница 28: ...Rev 1 00 Dec 13 2005 Page xxviii of l ...
Страница 50: ...Rev 1 00 Dec 13 2005 Page l of l ...
Страница 82: ...Section 1 Overview Rev 1 00 Dec 13 2005 Page 32 of 1286 REJ09B0158 0100 ...
Страница 122: ...Section 3 Instruction Set Rev 1 00 Dec 13 2005 Page 72 of 1286 REJ09B0158 0100 ...
Страница 146: ...Section 4 Pipelining Rev 1 00 Dec 13 2005 Page 96 of 1286 REJ09B0158 0100 ...
Страница 196: ...Section 6 Floating Point Unit FPU Rev 1 00 Dec 13 2005 Page 146 of 1286 REJ09B0158 0100 ...
Страница 292: ...Section 9 L Memory Rev 1 00 Dec 13 2005 Page 242 of 1286 REJ09B0158 0100 ...
Страница 450: ...Section 11 Local Bus State Controller LBSC Rev 1 00 Dec 13 2005 Page 400 of 1286 REJ09B0158 0100 ...
Страница 492: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Dec 13 2005 Page 442 of 1286 REJ09B0158 0100 ...
Страница 674: ...Section 15 Clock Pulse Generator CPG Rev 1 00 Dec 13 2005 Page 624 of 1286 REJ09B0158 0100 ...
Страница 692: ...Section 16 Watchdog Timer and Reset Rev 1 00 Dec 13 2005 Page 642 of 1286 REJ09B0158 0100 ...
Страница 726: ...Section 18 Timer Unit TMU Rev 1 00 Dec 13 2005 Page 676 of 1286 REJ09B0158 0100 ...
Страница 1004: ...Section 24 Multimedia Card Interface MMCIF Rev 1 00 Dec 13 2005 Page 954 of 1286 REJ09B0158 0100 ...
Страница 1032: ...Section 25 Audio Codec Interface HAC Rev 1 00 Dec 13 2005 Page 982 of 1286 REJ09B0158 0100 ...
Страница 1070: ...Section 26 Serial Sound Interface SSI Module Rev 1 00 Dec 13 2005 Page 1020 of 1286 REJ09B0158 0100 ...
Страница 1104: ...Section 27 NAND Flash Memory Controller FLCTL Rev 1 00 Dec 13 2005 Page 1054 of 1286 REJ09B0158 0100 ...
Страница 1150: ...Section 28 General Purpose I O GPIO Rev 1 00 Dec 13 2005 Page 1100 of 1286 REJ09B0158 0100 ...
Страница 1184: ...Section 29 User Break Controller UBC Rev 1 00 Dec 13 2005 Page 1134 of 1286 REJ09B0158 0100 ...
Страница 1266: ...Section 31 Electrical Characteristics Rev 1 00 Dec 13 2005 Page 1216 of 1286 REJ09B0158 0100 ...
Страница 1328: ...Appendix Rev 1 00 Dec 13 2005 Page 1278 of 1286 REJ09B0158 0100 ...
Страница 1336: ...Rev 1 00 Dec 13 2005 Page 1286 of 1286 REJ09B0158 0100 ...
Страница 1339: ......
Страница 1340: ...SH7780 Hardware Manual ...