EM78M611E
Universal Serial Bus Series Microcontroller
16 •
••
•
Product Specification (V1.1) 11.22.2006
(This specification is subject to change without further notice)
RF [2] USB Suspend interrupt flag. It will be set when the EM78M611E finds the
USB Suspend Signal on USB bus. This bit is cleared by the firmware.
RF [3] USB Reset interrupt flag. It will be set when the host issues the USB Reset
signal.
RF [4] P74/P75/P76/P77 Port state change interrupt flag.
In PS2 Mode, only pins configured as inputs can cause this interrupt to occur.
These pins (P74, P75, P76 and P77) are compared with the value latched on
the last read of Port 7.
In USB Mode, P76 and P77 have this function.
NOTE
R F[4]: Port State Change Interrupt Flag,
EM78M611
USB Mode –P76 and P77 DO NOT have interrupt function.
PS2 Mode – P74/P75/P76/P77 have interrupt function.
EM78M611E
P74/P75/P76/P77 all have interrupt function (in USB & PS2 mode)
RF [5, 6] SE1 / SE2 Pattern Detect Interrupt flag. These two flags are used for Pattern
detect application.
RF [7] USB Host Resume interrupt flag. It will be set only in Dual clock mode when
the USB suspend signal becomes low.
NOTE
RF [7]: USB Host Resume_IF
In EM78M611, this bit is always ‘1’. It is not for use.
In EM78M611E, this bit is O.K. for use.
8.2.3 Control Registers Some special purpose registers are available for special control purposes. Except for
the Accumulator (ACC), these registers must be read and written with special
instructions. One of these registers, CONT, can only be read by the instruction
"CONTR" and written by "CONTW" instruction. The other special control registers can
be read by the instruction "IOR" and written by the instruction "IOW".
The following paragraphs describe only the general functions of the control registers.
8.2.3.1 A (Accumulator)
The accumulator is an 8-bit register that holds operands and results of arithmetic
calculations. It is not addressable. After an interrupt occurs, the Accumulator is
auto-saved by hardware.