90 lines
4.4 KiB
Plaintext
90 lines
4.4 KiB
Plaintext
8. Commands of the processing of the interruptions.
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The Commands of the processing of the interruptions fill the field of
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microinstruction m/c BH1. The chip KM1804BH1 - is 8-digits microprogramming
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scheme (with ability to be increased) of the vector priority interruption,
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which produces processing by priority of inquiry for interruptions, which
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enter by eight buses from different devices.
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Commands of management m/c and types of their writing are brought Below:
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1)RESET - a command for cleaning;
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can be without or with one operand;
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a)command RESET without operands conducts general clearing.
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While this command is executed the zeroizing of the register of
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the condition occures and trigger of the permit of the request
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of the interruption moves into condition, which allows leaving of
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the request of the interruption, a.w. system of the interruption
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will react on the request of any priority
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b)RESET MR - a clearing the register of the mask(zeroizing all
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digits of the register of the mask); as a result
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all interruptions will be unmasked.
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c)RESET IR - clearing of the register of the interruption.
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2)CLR - a command of bitwise cleaning of internal registers of the chip;
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it is used to registers of the interruptions and masks:
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a)IR - can be realized by signals from data buse, register of the
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mask and register of the vector. For exemple:
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CLR IR ,00011000% ; \clean 4 and 5 digits
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CLR IR , MR; \clean that digits of the register of the
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\interruptions, for which the numeral in
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\ register of the mask corresponds
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CLR IR , VR ; \occurs zeroizing those of IR ,
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\which corresponds with the vector of the
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\interruptions,located in register of the vector
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b)MR - realized by signals from data buses.
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3)SET - is a command of the bitwise installing of the register of the mask.
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For instance:
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SET MR , 11100000%;\masking hte interruptions,
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\which enter from 8,7 and 6 external devices;
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\the rest of digits of the register of the mask
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\are not touched
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4)READ - a command of the reading of the register m/c;
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it is used to registers of the mask, of the condition and of the
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vector:
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a)READ MR;
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b)READ SR;
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c)READ VR;
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While these commands are executing the signals, reflecting by
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condition of register of the mask, conditions and vector, are
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given on data bus.
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5)DI - a prohibition of the request of the interruptions(occurs zeroizing
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of the trigger of the permiting of the request of the interruption).
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(command is without operands)
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6)EI - the permittion of the request of the interruption; the command acts
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opposite command DI. (command is without operands)
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For all commands, where as second operand appears numerical value, shortcut
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form is also equitable - without direct inputting of the data; then the data
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will enter on data bus not from the memory of the microinstructions, but
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forming in process of the performing of the microinstruction on the kit of
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the microprocessor. For instance:
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{OE_ALU; \allow the issue of the result of the execution
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\of operation on data bus in ALU
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XOR R1,R4; \execute the operation in ALU
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CLR MR; } \clean those digits of the register of the mask
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\that correspond to digits R1 and
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\R4 of ALU and do not coincide
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All commands, which read or give on data bus some values, work from younger
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digits of the bus; for instance, the command
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READ VR;
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will issue the value of 3-digital register of the vector on three younger
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digits of the data bus.
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