Section 6
Bus Controller (BSC)
Rev.2.00 Jun. 28, 2007 Page 165 of 666
REJ09B0311-0200
(2)
16-Bit Access Space
With the 16-bit access space, the upper byte data bus (D15 to D8) and lower byte data bus (D7 to
D0) are used for accesses. The amount of data that can be accessed at one time is one byte or one
word.
Figures 6.12 and 6.13 illustrate data alignment control for the 16-bit access space. Figure 6.12
shows the data alignment when the data endian format is specified as big endian. Figure 6.13
shows the data alignment when the data endian format is specified as little endian.
In big endian, byte access for an even address is performed by using the upper byte data bus and
byte access for an odd address is performed by using the lower byte data bus.
In little endian, byte access for an even address is performed by using the lower byte data bus, and
byte access for an odd address is performed by using the upper byte data bus.
Longword
Access
Address
Access
Count
15
31
24
0
7
Access
Size
Byte
Byte
Byte
Byte
Byte
Word
Word
Word
Word
Byte
Byte
Word
1
1
1
1st
1st
1st
1st
2nd
1st
2nd
1st
2nd
3rd
2
2
3
Bus
Cycle
Data Size
Data bus
D15
D8 D7
D0
RD
15
23
8
8
7
0
7
0
7
0
23
16
16
15
8
31
24
7
0
15
8
7
0
LHWR
/
LUB
LLWR
/
LLB
Strobe signal
Even
(2n)
(2n)
Odd
Even
(2n+1)
Odd
(2n+1)
Odd
(2n+1)
Even
(2n)
Figure 6.12 Access Sizes and Data Alignment Control for 16-Bit Access Space (Big Endian)
Содержание H8SX/1650
Страница 2: ...Rev 2 00 Jun 28 2007 Page ii of xxii...
Страница 106: ...Section 4 Exception Handling Rev 2 00 Jun 28 2007 Page 84 of 666 REJ09B0311 0200...
Страница 142: ...Section 5 Interrupt Controller Rev 2 00 Jun 28 2007 Page 120 of 666 REJ09B0311 0200...
Страница 326: ...Section 8 I O Ports Rev 2 00 Jun 28 2007 Page 304 of 666 REJ09B0311 0200...
Страница 470: ...Section 12 Watchdog Timer WDT Rev 2 00 Jun 28 2007 Page 448 of 666 REJ09B0311 0200...
Страница 546: ...Section 13 Serial Communication Interface SCI Rev 2 00 Jun 28 2007 Page 524 of 666 REJ09B0311 0200...
Страница 566: ...Section 14 A D Converter Rev 2 00 Jun 28 2007 Page 544 of 666 REJ09B0311 0200...
Страница 574: ...Section 16 RAM Rev 2 00 Jun 28 2007 Page 552 of 666 REJ09B0311 0200...
Страница 584: ...Section 17 Clock Pulse Generator Rev 2 00 Jun 28 2007 Page 562 of 666 REJ09B0311 0200...
Страница 638: ...Section 19 List of Registers Rev 2 00 Jun 28 2007 Page 616 of 666 REJ09B0311 0200...
Страница 668: ...Section 20 Electrical Characteristics Rev 2 00 Jun 28 2007 Page 646 of 666 REJ09B0311 0200...
Страница 676: ...Appendix Rev 2 00 Jun 28 2007 Page 654 of 666 REJ09B0311 0200...
Страница 688: ...Rev 2 00 Jun 28 2007 Page 666 of 666 REJ09B0311 0200...
Страница 691: ......
Страница 692: ...H8SX 1650 Group Hardware Manual...