Oki MSM83C154S, MSM80C154S manual Bank

Page 17

¡ Semiconductor

MSM80C154S/83C154S

Program status word register (PSW)

NAME

ADDRESS

MSB

LSB

7

6

5

4

3

2

1

0

PSW

0D0H

CY

AC

F0

RS1

RS0

OV

F1

P

BIT LOCATION

FLAG

FUNCTION

PSW.0

P

Accumulator (ACC) parity indicator.

This bit is "1" when the "1" bit number in the accumulator is an odd number, and

"0" when an even number.

PSW.1

F1

User flag which may be set to "0" or "1" as desired by the user.

PSW.2

OV

Overflow flag which is set if the carry C6 from bit 6 of the ALU or CY is "1" as a

result of an arithmetic operation. The flag is also set to "1" if the resultant product

of executing multiplication instruction (MUL AB) is greater than 0FFH, but is reset

to "0" if the product is less than or equal to 0FFH.

PSW.3

RS0

RAM register bank switch

RS1

RS0

BANK

RAM ADDRESS

0

0

0

00H - 07H

PSW.4

RS1

0

1

1

08H - 0FH

1

0

2

10H - 17H

1

1

3

18H - 1FH

PSW.5

F0

User flag which may be set to "0" or "1" as desired by the user.

PSW.6

AC

Auxiliary carry flag.

This flag is set to "1" if a carry C3 is generated from bit 3 of the ALU as a result of

executing an arithmetic operation instruction.

In all other cases, the flag is reset to "0".

PSW.7

CY

Main carry flag.

This flag is set to "1" if a carry C7 is generated from bit 7 of the ALU as result of

executing an arithmetic operation instruction.

If a carry C7 is not generated, the flag is reset to "0".

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Image 17

Contents General Description Features¡SemiconductorSemiconductor MSM80C154S/83C154S Cmos 8-bit Microcontroller¡ Semiconductor MSM80C154S/83C154STIMER/COUNTER 0 Interrupt Signal2PORT Address DecoderPsen PIN Configuration TOP ViewPin Plastic DIP Pin Plastic QFP Reset44 P1.4 P1.5 P1.6 P1.7 25 P2.7 24 P2.6 23 P2.5 P2.4Pin Plastic Tqfp XTAL1 XTAL2 19 P3.7/RD 18 P3.6/WR Pin Plastic QFJ35 EA P3.0/RXD 34 NC 33 ALE P3.1/TXD ALE PIN DescriptionsMSM80C154S/83C154S¡ Semiconductor XTAL2 ¡ SemiconductorMSM80C154S/83C154SXTAL1 Registers Diagram of Special Function RegistersGate Special Function Registers Timer mode register TmodCPU is reset Power control register PconInterrupt signal Interrupt request flag for external interrupt Timer control register TconTcon TR1 TF0 TR0 IE1 IT1 IE0 IT0 Mode Serial port control register Scon REN Interrupt control bit for serial port Interrupt enable register IEReserved bit. The output data is 1 if the bit is read Overall interrupt control bitInterrupt priority register IP Priority is assigned when bit isPriority interrupt circuit control bit PCT PT2 PT1 PX1 PT0 PX0Bank Control register Iocon When this bit is set toIZC Received at a serial portTimer 2 control register T2CON Program Area Memory MapsBIT RAM HEX 0FF AddressingindirectregisterBANK3 BANK20FFH MSM80C154S/83C154S Diagram of Internal Data Memory RAM2FH 0FHRecommended Operating Conditions Absolute Maximum RatingsPort 0, ALE, Psen Electrical CharacteristicsDC Characteristics Maximum power supply current idle mode ICC mA Maximum power supply current normal operation ICC mAVO=0.1 Port 1, 2 Logical 1 to 0 Transition Output High Voltage Port 1, 2Logical 0 Input Current VI=0.1 Logical 1 Output Current 285 Output Measuring circuitsInput Address Setup Time ALE Signal WidthFalling Edge Psen Signal Width To ALE Falling Edge Address Hold TimeInstr External program memory read cyclePORT0 External data memory access AC characteristics External data memory write cycle External data memory read cycleParameter Symbol Min Max Unit Serial port I/O Extension Mode AC characteristicsInput Data ALE Shift ClockExternal Oscillator Signal AC Characteristics Measuring ConditionsXTAL1 external clock input waveform conditions External Clock Drive Waveform294 Basictiming TimingDiagram