SIC63616-(Rev. 1.0) NO. P12
3240-0412
2.2.2 Simultaneous high input to P1x ports (P10-P13)
Another way of executing initial reset externally is to input high level signals simultaneously to the P1x
ports (P10–P13) selected by a mask option.
Since this initial reset passes through the noise reject circuit, maintain the specified input port terminals
at high level for at least 1.5 msec (when the oscillation frequency f
OSC1
is 32.768 kHz) during normal
operation. The noise reject circuit does not operate immediately after turning the power on until the oscilla-
tion. The noise reject circuit does not operate immediately after turning the power on until the oscilla-
tion circuit starts oscillating. Therefore, maintain the specified input port terminals at high level for at least 1.5
msec (when the oscillation frequency f
OSC1
is 32.768 kHz) after oscillation starts.
Table 2.2.2.1 shows the combinations of P1x ports (P10–P13) that can be selected by a mask option.
Table 2.2.2.1 Combinations of P1x ports
Not use
P10
∗
P11
P10
∗
P11
∗
P12
P10
∗
P11
∗
P12
∗
P13
1
2
3
4
When, for instance, mask option 4 (P10
∗
P11
∗
P12
∗
P13) is selected, initial reset is executed when the signals
input to the four ports P10–P13 are all high at the same time. When 2 or 3 is selected, the initial reset is done
when a key entry including a combination of selected input ports is made.
Further, the time authorize circuit mask option is selected when this reset function is selected. The time
authorize circuit checks the input time of the simultaneous high input and performs initial reset if that time
is the defined time (1 to 2 sec) or more.
If using this function, make sure that the specified ports do not go high at the same time during ordinary
operation.
2.2.3 Internal register at initial resetting
Initial reset initializes the CPU as shown in Table 2.2.3.1.
The registers and flags which are not initialized by initial reset should be initialized in the program if neces-
sary.
In particular, the stack pointers SP1 and SP2 must be set as a pair because all the interrupts including NMI
are masked after initial reset until both the SP1 and SP2 stack pointers are set with software.
When data is written to the EXT register, the E flag is set and the following instruction will be executed in
the extended addressing mode. If an instruction which does not permit extended operation is used as the
following instruction, the operation is not guaranteed. Therefore, do not write data to the EXT register for
initialization only.
Refer to the "S1C63000 Core CPU Manual" for extended addressing and usable instructions.
Table 2.2.3.1 Initial values
Name
Data register A
Data register B
Extension register EXT
Index register X
Index register Y
Program counter
Stack pointer SP1
Stack pointer SP2
Zero flag
Carry flag
Interrupt flag
Extension flag
Queue register
CPU core
Symbol
A
B
EXT
X
Y
PC
SP1
SP2
Z
C
I
E
Q
Number of bits
4
4
8
16
16
16
8
8
1
1
1
1
16
Setting value
Undefined
Undefined
Undefined
Undefined
Undefined
0110H
Undefined
Undefined
Undefined
Undefined
0
0
Undefined
Name
RAM
Display memory
Other peripheral circuits
Peripheral circuits
Number of bits
4
4
–
Setting value
Undefined
Undefined
∗
∗
See Section 4.1, "Memory Map".