UPD65 NEC [NEC], UPD65 Datasheet - Page 12

• Manufacturer Part Number: UPD65
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER FOR INFRARED REMOTE CONTROL TRANSMISSION
• Manufacturer: NEC [NEC]

2.8 Arithmetic and Logic Unit (ALU): 4 Bits
manipulations with priority given to logical operations.
2.9 Flags
2.9.1 Status flag (F)
12
Operand Value of STTS Instruction
The arithmetic and logic unit (ALU), which refers to an arithmetic circuit consisting of 4 bits, executes simple
Pin and timer statuses can be checked by executing the STTS instruction to check the status flag.
The status flag is set (to 1) in the following cases.
• If the condition specified with the operand is met when the STTS instruction has been executed
• When STANDBY mode is released.
• When the release condition is met at the point of executing the HALT instruction. (In this case, the system
Conversely, the status flag is cleared (to 0) in the following cases:
• If the condition specified with the operand is not met when the STTS instruction has been executed.
• When the status flag has been set (to 1), the HALT instruction executed, but the release condition is not met
Note The use of STOP mode release for the S
b
0
1
3
is not placed in STANDBY mode.)
at the point of executing the HALT instruction. (In this case, the system is not placed in STANDBY mode.)
Either of the combinations
of b
b
0
0
1
1
2
2
, b
1
, and b
Table 2-1. Conditions for Status Flag (F) To Be Set by STTS Instruction
b
0
1
1
0
1
0
above.
b
0
1
0
1
0
High level is input to at least one of K
High level is input to at least one of K
High level is input to at least one of K
The down counter of the timer is 0.
High level is input to at least one of S
Data Sheet U14380EJ2V0DS00
[The following condition is added in addition to the above.]
2
pin must be enabled (bit 3 of P4 register is set to 1.)
Condition for Status Flag (F) To Be Set
I
I
I
0
, S
pins.
pins.
pins.
1
, and S
2
Note
pins.
PD64A, 65