Epson ARM.POWERED ARM720T - Manual (Page 25)

1: Introduction
ARM720T CORE CPU MANUAL EPSON 1-5
1.2 Coprocessors
The ARM720T processor has an internal coprocessor designated CP15 for internal control of
the device (see Chapter 3 Configuration ).
The ARM720T processor also includes a port for the connection of on-chip external
coprocessors. This enables extension of the ARM720T functionality in an
architecturally-consistent manner.
1.3 About the instruction set
The instruction set comprises ten basic instruction types:
• Two types use the on-chip arithmetic logic unit, barrel shifter, and multiplier to
perform high-speed operations on the data in a bank of 31 registers, each 32 bits
wide.
• Three types of instruction control the data transfer between memory and the
registers:
–
one optimized for flexibility of addressing
– one for rapid context switching
– one for swapping data.
• Two instructions control the flow and privilege level of execution.
• Three types are dedicated to the control of external coprocessors. These enable you
to extend the functionality of the instruction set off-chip in an open and uniform
way.
The ARM instruction set is a good target for compilers of many different high-level languages.
Where required for critical code segments, assembly code programming is also
straightforward.