H8S2245 datasheet(196/818 Pages) RENESAS

부품명	H8S2245

상세설명	Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series

PDF	818 Pages

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제조업체	RENESAS [Renesas Technology Corp]

홈페이지	http://www.renesas.com

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Section 6 Bus Controller

Rev.3.00 Mar. 26, 2007 Page 154 of 772

REJ09B0355-0300

D15

D8 D7

Upper data bus

Lower data bus

Byte size

Word size

1st bus cycle

2nd bus cycle

Longword size

1st bus cycle

2nd bus cycle

3rd bus cycle

4th bus cycle

Figure 6.8 Access Sizes and Data Alignment Control (8-Bit Access Space)

16-Bit Access Space

Figure 6.9 illustrates data alignment control for the 16-bit access space. With the 16-bit access

space, the upper data bus (D

15 to D8) and lower 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, and a longword transfer

instruction is executed as two word transfer instructions.

In byte access, whether the upper or lower data bus is used is determined by whether the address is

even or odd. The upper data bus is used for an even address, and the lower data bus for an odd

address.

D15

D8 D7

Upper data bus

Byte size

Word size

1st bus cycle

2nd bus cycle

Longword

size

• Even address

Byte size

• Odd address

Lower data bus

Figure 6.9 Access Sizes and Data Alignment Control (16-Bit Access Space)

H8S2245 데이터시트(PDF) 196 Page - Renesas Technology Corp