Claims
- 1. A protection circuit for selectively providing data access to a peripheral device that is capable of executing commands in a system having a common serial data link, comprising:
- (a) an interface circuit connected to provide a data interface to said common serial data link;
- (b) a protocol shift register operatively connected to said interface circuit and configured for storing control information and ID information received from said common serial data link, said control information having at least one embedded command executable by said peripheral device;
- (c) an internal storage register from storing an ID template;
- (d) a compare circuit connected and configured to compare said ID information stored in said protocol shift register with said ID template stored in said internal storage register;
- (e) a decode circuit connected to receive said control information from said protocol shift register and configured to provide logic outputs reflecting said embedded command(s) in said control information, said logic outputs executable by said peripheral device, said embedded command(s) reads or writes to said peripheral device or reads or writes to said internal storage register;
- (f) wherein said compare circuit, said decode circuit, said internal storage register, and said interface circuit are operatively connected together in such relation that:
- (i) whenever said decode circuit indicates that said embedded command(s) is to read said ID template from said internal storage register, said embedded command(s) will be executed by said peripheral device and said ID template will be read to said common serial data link;
- (ii) but any other embedded command(s) will be executed by said peripheral device only if said compare circuit indicates a match between said ID information and said ID template.
- 2. The protection circuit of claim 1, wherein said internal storage register is a non-volatile register.
- 3. The protection circuit of claim 1, wherein said interface circuit is a wireless interface circuit.
- 4. The protection circuit of claim 1, wherein said interface circuit is an RF interface circuit.
- 5. The protection circuit of claim 1, wherein said protocol shift register is configured to hold more than 32 bits of information.
- 6. The protection circuit of claim 1, wherein said protocol shift register is configured to hold no more than 32 bits of information.
- 7. The protection circuit of claim 1, wherein said protocol shift register comprises a random access memory and said protocol shift register is operable to receive memory control information for said random access memory.
- 8. The protection circuit of claim 1, wherein said common serial data link comprises at least three data lines.
- 9. A protection system to selectively access at least one peripheral device that is capable of executing a plurality of commands, said protection system comprising:
- (a) a data link;
- (b) an interface module to provide an interface to said data line;
- (c) a first storage module operatively connected to said interface module and configured to store control information and identification information received from said data link, said control information comprising at least one command executable by said peripheral device;
- (d) a second storage module for storing an identification template;
- (e) a compare module connected and configured to compare said identification information stored in said first storage module with said identification template stored in said second storage module;
- (f) a decode module connected to receive said control information from said first storage module and configured to provide logic outputs reflecting said command(s), said logic outputs executable by said peripheral device, said command(s) read or write to said peripheral device or read or write to said second storage module;
- (g) wherein said compare module, said decode module, said first storage module, said second storage module, and said interface module are coupled together in such relation that:
- (i) whenever said decode module indicates that said command(s) is to read said identification template from said second storage module, said command will be executed by said peripheral device and said identification template will be read to said data link;
- (ii) but any other command(s) will be executed by said peripheral device only if said compare module indicates a match between said identification information and said identification template.
- 10. The protection system of claim 9, wherein said first storage module is a protocol shift register.
- 11. The protection system of claim 9, wherein said interface module is a wireless interface circuit.
- 12. The protection system of claim 9, wherein said interface module is an RF interface circuit.
- 13. The protection system of claim 10, wherein said protocol shift register is configured to at least 16 bits.
- 14. The protection system of claim 9, wherein said second storage module is an internal storage register.
- 15. The protection system of claim 9, wherein said first storage module is a non-volatile register.
- 16. The protection system of claim 9, wherein said data link is serial.
- 17. The protection system of claim 9, wherein said data link comprises at least three data wires.
- 18. A system for accessing at least one selected peripheral unit, comprising:
- (a) a central processing unit for transmitting and receiving data and for transmitting control information and identification information;
- (b) a data link coupled to said central processing unit for communicating said data, said control information, and said identification information;
- (c) at least one protection system associated with said selected peripheral unit, said protection system comprising
- (c1) an interface module to provide an interface to said data link, such that said interface module receives said data, said control information, and said identification information;
- (c2) a first storage module operatively connected to said interface module and configured to hold control information and identification information received from said data link, said control information comprising at least one command executable by said peripheral device;
- (c3) a second storage module for storing an identification template;
- (c4) a compare module connected and configured to compare said identification information stored in said first storage module with said identification template stored in said second storage module;
- (c5) a decode module connected to receive said control information stored in said first storage module and configured to provide logic outputs reflecting said command(s), said logic outputs executable by said peripheral device, said command(s) read or write to said peripheral device or read or write to said second storage module;
- (c6) wherein said compare module, said decode module, said first storage module, said second storage module, and said interface module are coupled together in such relation that:
- (i) whenever said decode module indicates that said command(s) is to read said identification template stored in said second storage module, said command will be executed by said peripheral device and said identification template will be read to said data link;
- (ii) but any other command(s) will be executed by said peripheral device only if said compare module indicates a match between said identification information and said identification template.
- 19. The protection system of claim 18, wherein data link is a serial data link.
- 20. The protection system of claim 18, wherein said data link comprises at least three data wires.
Parent Case Info
This is a continuation of application Ser. No. 202,874, filed Jun. 3, 1988 now abandoned.
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Continuations (1)
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Number |
Date |
Country |
Parent |
202874 |
Jun 1988 |
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