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CHAPTER 1 OVERVIEW
1.1
MB91107/MB91108 Features
The MB91107/MB91108 is a standard single-chip microcontroller that employs a 32-bit
RISC CPU (FR series) as core. The MB91107/MB91108 incorporates bus control
mechanisms and various I/O resources for embedded control as required for allowing
high-performance, high-speed CPU processing. Because the 32-bit CPU of the
MB91107/MB91108 supports accesses to large address spaces, external bus access is
standard. On the other hand, to increase the speed by which the CPU executes
instructions, a 1 Kbyte instruction cache and RAM (MB91107: 128 Kbytes, MB91108:
160 Kbytes) are built in.
The MB91107/MB91108 provides ideal specifications for embedded use in systems
requiring high CPU performance, such as a navigation system, high-performance FAX,
and printer control.
s MB91107/MB91108 Features
r FR-CPU
32-bit RISC, load/store architecture, and 5-stage pipeline
Operating frequency: Internal 50 MHz [external 25 MHz] (PLL used, source oscillation of
12.5 MHz)
General-purpose registers: 32 bit × 16
16-bit fixed-length instructions (basic instructions), one instruction per cycle
Such instructions as memory-to-memory transfer, bit processing, and barrel shift, which are
ideal for embedded use
High-level language instructions, such as instruction for function entry and exit and
instructions for register multiload and multistore
Register interlock function, which facilitates assembler coding
Branch instructions with delayed slot, which reduce overhead during branch processing
Support at the built-in and instruction level of the multiplier unit
Signed 32-bit multiplication in 5 cycles
Signed 16-bit multiplication in 3 cycles
Interrupts (PC and PS save) at 6 cycles and 16 priority levels
r Bus interface
Used clock doubler: Internal 50 MHz and external 25 MHz operations
25-bit address bus (32 Mbytes space)
16-bit and 8-bit data buses
Basic external bus cycle: 2 clock cycles
8 chip select outputs that can be set in minimum units of 64 Kbytes