HD6473032F16 Datasheet, PDF (93/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

3.4 Operating Mode Descriptions
Section 3 MCU Operating Modes
3.4.1 Mode 1
Ports 1, 2, and 5 function as address pins A₁₉ to A₀, permitting access to a maximum 1-Mbyte
address space. The initial bus mode after a reset is 8 bits, with 8-bit access to all areas. If at least
one area is designated for 16-bit access in ABWCR, the bus mode switches to 16 bits.
3.4.2 Mode 2
Ports 1, 2, and 5 function as address pins A₁₉ to A₀, permitting access to a maximum 1-Mbyte
address space. The initial bus mode after a reset is 16 bits, with 16-bit access to all areas. If all
areas are designated for 8-bit access in ABWCR, the bus mode switches to 8 bits.
3.4.3 Mode 3
Ports 1, 2, and 5 and part of port A function as address pins A₂₃ to A₀, permitting access to a
maximum 16-Mbyte address space. The initial bus mode after a reset is 8 bits, with 8-bit access to
all areas. If at least one area is designated for 16-bit access in ABWCR, the bus mode switches to
16 bits. A₂₃ to A₂₁ are valid when 0 is written in bits 7 to 5 of the bus release control register
(BRCR). (In this mode A₂₀ is always used for address output.)
3.4.4 Mode 4
Ports 1, 2, and 5 and part of port A function as address pins A₂₃ to A₀, permitting access to a
maximum 16-Mbyte address space. The initial bus mode after a reset is 16 bits, with 16-bit access
to all areas. If all areas are designated for 8-bit access in ABWCR, the bus mode switches to
8 bits. A₂₃ to A₂₁ are valid when 0 is written in bits 7 to 5 of BRCR. (In this mode A₂₀ is always
used for address output.)
3.4.5 Mode 5
Ports 1, 2, and 5 can function as address pins A₁₉ to A₀, permitting access to a maximum 1-Mbyte
address space, but following a reset they are input ports. To use ports 1, 2, and 5 as an address bus,
the corresponding bits in their data direction registers (P1DDR, P2DDR, and P5DDR) must be set
to 1. The initial bus mode after a reset is 8 bits, with 8-bit access to all areas. If at least one area is
designated for 16-bit access in ABWCR, the bus mode switches to 16 bits.
Rev. 3.00 Mar 21, 2006 page 63 of 814
REJ09B0302-0300