Integrated circuit with a serial port having only one pin
First Claim
1. An integrated circuit comprising;
- a clock terminal;
a first module coupled to said clock terminal wherein said first module receives a clock signal from said clock terminal and generates a buffered clock signal, said buffered clock signal and said clock signal having a common frequency;
a second module having a clock input line coupled to said first module wherein said buffered clock signal is supplied to said clock input line of said second module; and
a serial port having a clock input line coupled to said first module wherein said buffered clock signal is supplied to said clock input line of said serial port and further wherein said serial port further comprises;
a plurality of storage elements wherein each storage element is serially coupled to another storage element in said plurality of storage elements; and
a bidirectional pin coupled to at least one storage element in said plurality of storage elements wherein said bidirectional pin is the only pin in said serial port, and said bidirectional pin is used to transfer information serially from and to said integrated circuit;
wherein said serial port waits for a predetermined time period after transmission of a signal on said bidirectional pin to become sensitive to a signal received on said bidirectional pin.
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Accused Products
Abstract
A host adapter integrated circuit that contains data transfer modules has a serial port that uses a single serial port pin to communicate with a slave serial port input-output integrated circuit that interfaces to various resources that are included in a support circuit. The serial port forms a packet from each byte of information to be transferred from a module to the slave device by adding a start bit before the byte, followed by a parity bit at the end of the byte and followed by a stop bit. After transmitting the packet, the serial port waits for an acknowledge packet from the slave serial port input-output integrated circuit, for example for two clock cycles after transmission of the packet. For synchronous operation, a common oscillator drives the clock signal on the slave serial port input-output integrated circuit and host adapter integrated circuit. The serial port pin in the host adapter integrated circuit is connected to a shifter circuit in the serial port that serially clocks data from the serial port pin and passes the data parallelly to a bus in the host adapter integrated circuit and vice versa.
53 Citations
30 Claims
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1. An integrated circuit comprising;
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a clock terminal; a first module coupled to said clock terminal wherein said first module receives a clock signal from said clock terminal and generates a buffered clock signal, said buffered clock signal and said clock signal having a common frequency; a second module having a clock input line coupled to said first module wherein said buffered clock signal is supplied to said clock input line of said second module; and a serial port having a clock input line coupled to said first module wherein said buffered clock signal is supplied to said clock input line of said serial port and further wherein said serial port further comprises; a plurality of storage elements wherein each storage element is serially coupled to another storage element in said plurality of storage elements; and a bidirectional pin coupled to at least one storage element in said plurality of storage elements wherein said bidirectional pin is the only pin in said serial port, and said bidirectional pin is used to transfer information serially from and to said integrated circuit; wherein said serial port waits for a predetermined time period after transmission of a signal on said bidirectional pin to become sensitive to a signal received on said bidirectional pin. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 13, 14, 15)
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- 11. The integrated circuit of 10, wherein each of said command packet and said acknowledge packet has a start bit at the beginning and a stop bit at the end, said start bit having a first value and said stop bit having a second value different from said first value.
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16. An integrated circuit comprising:
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a clock terminal; a first module coupled to said clock terminal wherein said first module receives a clock signal from said clock terminal and generates a buffered clock signal, said buffered clock signal and said clock signal having a common frequency; a second module having a clock input line coupled to said first module wherein said buffered clock signal is supplied to said clock input line of said second module; and a serial port having a clock input line coupled to said first module wherein said buffered clock signal is supplied to said clock input line of said serial port and further wherein said serial port further comprises; a plurality of storage elements wherein each storage element is serially coupled to another storage element in said plurality of storage elements; and a bidirectional pin coupled to at least one storage element in said plurality of storage elements wherein said bidirectional pin is the only pin in said serial port, and said bidirectional pin is used to transfer information serially from and to said integrated circuit; wherein said serial port waits for a predetermined time period after receipt of a signal on said bidirectional pin before transmission of a signal on said bidirectional pin. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 29, 30)
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- 27. The integrated circuit of 26, wherein each of said first packet and said second packet has a start bit at the beginning and a stop bit at the end, said start bit having a first value and said stop bit having a second value different from said first value.
Specification