3069RF-ZTAT Datasheet, PDF (85/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

3.4.4 Mode 4
Ports 1, 2, 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, 5, and part of port A can function as address pins A₂₃ to A₀, permitting access to a
maximum 16-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. For A₂₃ to A₂₀ output, write 0 in bits 7 to 4 of BRCR. Products with
on-chip flash memory support on-board programming which enables programming of the flash
memory. 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.
3.4.6 Mode 7
This mode operates using the on-chip ROM, RAM, and registers. All I/O ports are available.
Mode 7 supports a 1-Mbyte address space.
Products with on-chip flash memory support on-board programming which enables programming
of the flash memory.
Rev. 5.0, 09/04, page 63 of 978