Epson S1C88650 - Manual (Page 57)

S1C88650 TECHNICAL MANUAL EPSON 49
5 PERIPHERAL CIRCUITS AND THEIR OPERATION (Input Ports)
KCP00–KCP07: 00FF52H
Sets the interrupt generation condition (interrupt
generation timing) for input port terminals K00–
K07.
When "1" is written: Falling edge
When "0" is written: Rising edge
Reading:
Valid
KCP0x is the input comparison register which
corresponds to the input port K0x. Interrupt in
those ports which have been set to "1" is generated
on the falling edge of the input and in those set to
"0" on the rising edge.
At initial reset, this register is set to "1" (falling
edge).
CTK00L–CTK02L: 00FF58H•D0–D2
Sets the input level check time of the chattering-
eliminate circuit for the K00–K03 input port
interrupts as shown in Table 5.5.5.2.
Table 5.5.5.2 Setting the input level check time
CTK02L
1
1
1
1
0
0
0
0
CTK01L
1
1
0
0
1
1
0
0
CTK00L
1
0
1
0
1
0
1
0
Input level check time [sec]
4/f OSC3
2/f OSC3
1/f OSC3
4096/f OSC1
2048/f OSC1
512/f OSC1
128/f OSC1
None
Be sure to disable interrupts before changing the
contents of this register. Unnecessary interrupts
may occur if the register is changed when the
corresponding input port interrupts have been
enabled by the interrupt enable register EK0x.
At initial reset, this register is set to "0" (None).
CTK00H–CTK02H: 00FF58H•D4–D6
Sets the input level check time of the chattering-
eliminate circuit for the K04–K07 input port
interrupts as shown in Table 5.5.5.3.
Table 5.5.5.3 Setting the input level check time
CTK02H
1
1
1
1
0
0
0
0
CTK01H
1
1
0
0
1
1
0
0
CTK00H
1
0
1
0
1
0
1
0
Input level check time [sec]
4/f OSC3
2/f OSC3
1/f OSC3
4096/f OSC1
2048/f OSC1
512/f OSC1
128/f OSC1
None
Be sure to disable interrupts before changing the
contents of this register. Unnecessary interrupt may
occur if the register is changed when the
corresponding input port interrupts have been
enabled by the interrupt enable register EK0x.
At initial reset, this register is set to "0" (None).
PK00, PK01: 00FF20H•D6, D7
Sets the input interrupt priority level. PK00 and
PK01 are the interrupt priority registers
corresponding to the input interrupts.
Table 5.5.5.4 shows the interrupt priority level
which can be set by this register.
Table 5.5.5.4 Interrupt priority level settings
PK01 PK00 Interrupt priority level
1
1
0
0
1
0
1
0
Level 3 (IRQ3)
Level 2 (IRQ2)
Level 1 (IRQ1)
Level 0 (None)
At initial reset, this register is set to "0" (level 0).
EK00–EK07: 00FF24H
How interrupt generation to the CPU is permitted
or prohibited.
When "1" is written: Interrupt permitted
When "0" is written: Interrupt prohibited
Reading:
Valid
EK0x is the interrupt enable register which
correspond to the input port K0x.
Interrupt is permitted in those terminals set to "1"
and prohibited in those set to "0".
At initial reset, this register is set to "0" (interrupt
prohibited).
FK00–FK07: 00FF28H
Indicates the generation state for an input interrupt.
When "1" is read: Interrupt factor present
When "0" is read: Interrupt factor not present
When "1" is written: Reset factor flag
When "0" is written: Invalid
The interrupt factor flag FK0x corresponds to K0x is
set to "1" by the occurrence of an interrupt
generation condition.
When set in this manner, if the corresponding
interrupt enable register is set to "1" and the
corresponding interrupt priority register is set to a
higher level than the setting of interrupt flags (I0
and I1), an interrupt will be generated to the CPU.
Regardless of the interrupt enable register and
interrupt priority register settings, the interrupt
factor flag will be set to "1" by the occurrence of an
interrupt generation condition.
To accept the subsequent interrupt after interrupt
generation, re-setting of the interrupt flags (set
interrupt flag to lower level than the level indicated
by the interrupt priority registers, or execute the
RETE instruction) and interrupt factor flag reset are
necessary. The interrupt factor flag is reset to "0" by
writing "1".
At initial reset, this flag is all reset to "0".