H8S2426 Datasheet, PDF (111/1302 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family / H8S/2400 Series

Section 3 MCU Operating Modes
3.3.4 Mode 4
The CPU can access a 16-Mbyte address space in advanced mode. The on-chip ROM is enabled.
The program in the on-chip ROM connected to the first half of area 0 is executed.
Ports A to C function as input ports immediately after a reset, but can be set to function as an
address bus depending on each port register setting. Port D functions as a data bus and parts of
ports F to H function as bus control signals. For details on function switching of ports A to C, see
section 10, I/O Ports.
The initial bus mode immediately after a reset is 8 bits, with 8-bit access to all areas. However, if
16-bit access is designated for any one of the areas by the bus controller, the bus mode switches to
16 bits and port E functions as a data bus.
In the flash memory version, user program mode is entered by setting the SWE bit in FMCMDEN
to 1.
3.3.5 Mode 7
The CPU can access a 16-Mbyte address space in advanced mode. The on-chip ROM is enabled,
and the LSI starts up in single-chip mode. External address spaces cannot be used in single-chip
mode.
The initial mode immediately after a reset is single-chip mode, with all I/O ports available for use
as input/output ports. However, setting the EXPE bit in SYSCR to 1 switches the mode to an
externally expanded mode in which the external address spaces are enabled. When an externally
expanded mode is selected, all areas are initially designated as a 16-bit access space. The functions
of pins in ports A to H are the same as those in an externally expanded mode with on-chip ROM
enabled.
In the flash memory version, user program mode is entered by setting the SWE bit in FMCMDEN
to 1.
Rev. 1.00 Sep. 19, 2008 Page 83 of 1270
REJ09B0466-0100