EM78815
8-Bit Microcontroller
7.6 Wake-up
The controller provides a power saving mode:
(1) Sleep mode, RA (7) = 0 + "SLEP" instruction
The controller will turn off all the CPU and crystal. User has to turn off by software
all the other circuits with power control like Keytone control or PLL control (which
has an enable register).
Wake-up from Sleep mode:
(1) WDT time out
(2) External interrupt
(3) /Reset pull low
All these cases will reset the controller, and run the program at address zero. The
status is the same as that of the power-on reset.
7.7 Interrupt
RE and RF are the interrupt status registers which record the interrupt request in flag
bits. The IOCE and IOCF are the interrupt mask registers. The TCC timer, Counter 1
and Counter 2 are internal interrupt sources. P70 ~ P77 (INT0 ~ INT7) are external
interrupt input with external interrupt sources. If the interrupts come from these
interrupt sources, then the RE or RF register will generate a '1' flag to the
corresponding register if the IOCE or IOCF registers are enabled. Global interrupt is
enabled by ENI instruction and is disabled by DISI instruction. When one of the
interrupts (when enabled) is generated, it will cause the next instruction to be fetched
from address 008H. Once in the interrupt service routine, the source of the interrupt
can be determined by polling the flag bits in the RE and RF registers. The interrupt
flag bit must be cleared by software before leaving the interrupt service routine and
enabling interrupts, to avoid recursive interrupts.
7.8 Instruction Set
Instruction set has the following features:
(1) Every bit of any register can be set, cleared, or tested directly.
(2) The I/O register can be regarded as general register. That is, the same instruction
can operates on I/O register.
The symbol "R" represents a register designator which specifies which one of the 64
registers (including operational registers and general purpose registers) is to be
utilized by the instruction. Bits 6 and 7 in R4 determine the selected register bank.
"b'' represents a bit field designator which selects the number of the bit, located in the
register "R'', affected by the operation. "k'' represents an 8 or 10-bit constant or literal
value.
Product Specification (V2.4) 08.01.2004
(This specification is subject to change without further notice)
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ELAN [ ELAN MICROELECTRONICS CORP ]
