JPS62257U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a modulation circuit showing an embodiment of the present invention, and FIGS.
6250RPI, 1600RPI, 8 in the diagram
This is a time chart showing the modulation operation of 00RPI. REG ₁ , ₂ : Register, PROM: Programmable read-only memory, FF ₁ , ₂ ,
₃ : Flip-flop, EOR ₁ , ₂ : Exclusive OR gate, CHK: Parity checker, E
RR: Error indication signal, WTDi: Modulated write signal bit i, WTCTL: Parallel load instruction signal, FRMW: Format write instruction signal, INVi: Inverted write instruction signal, FRM:
Write format instruction signal, BITi: i-bit write data, CLK ₁ , ₂ , ₃ : clock signal, M1600: 1600RPI mode instruction signal, M800: 800PRPI mode instruction signal.

Amendment June 13, 1981 The scope of claims for utility model registration is amended as follows.

[Claims for Utility Model Registration] A modulation circuit for a magnetic tape device operating with GCR, PE and NRZI modulation methods, comprising a 4-bit first register for temporarily storing input data to be modulated; A PROM into which data is input from the register No. 1 and receives a modulation mode instruction and converts the input data into modulation data determined by the modulation mode instruction , and a PROM 5 that temporarily stores the modulation data from the PROM.
bit second register and data from the second register, NR
and a modulation circuit that performs modulation using the Z1 modulation method , and when the GCR mode is instructed as the modulation mode, the PROM modulates the 5-bit data by using the 4-bit data stored in the first register as an address. Second
When PE mode is specified as the modulation mode, outputs 2-bit data to the second register using the 2-bit data stored in the first register as an address. and when NRZ1 mode is specified as the modulation mode, the 1-bit data stored in the first register is used as an address to output 1-bit data to the second register and the modulation mode is set. A modulation circuit characterized by:

Claims (1)

[Claims for Utility Model Registration] (1) A modulation circuit for a magnetic tape device operating with different modulation methods such as GCR, PE, or NRZI, which comprises a first register for temporarily storing data, and the first register described above. A PROM that converts data input from a register into a data pattern instructed by giving each modulation mode instruction;
and a second register for temporarily storing the conversion data of M, and is characterized in that the timing of the clock for setting data in the first and second registers and PRM is different depending on each modulation mode. Modulation circuit. (2) A modulation circuit for a magnetic tape device that operates with different modulation methods such as GCR, PE, or NRZI, which includes a first register for temporarily storing data, and a modulation circuit for each modulation method for inputting data from the first register. A PROM that converts into a data pattern specified by giving a mode instruction;
The data stored in the second register is read out at different timings depending on each modulation mode, and a parity checker is provided, allowing the GCR system to be used. To check the modulated signal in
Claims for Utility Model Registration characterized in that the sum of the parities of each track of the data sub-group is determined by the above-mentioned parity checker, and it is checked whether the above-mentioned sum is the same at the beginning and end of the group. The modulation circuit according to item 1.