Along with monolithic integrated circuit application unceasingly thorough, constitutes the multi-computer system by many monolithic integrated circuits to be getting more and more. Between many monolithic integrated circuits carries on the exchange of information by many machine communication to constitute a whole. Decomposes the single monolithic integrated circuit’s work to many monolithic integrated circuits completes, on the one hand may enhance system’s each performance, on the other hand may simplify system’s hardware design.
When carries on the long-distance transmission, generally uses the asynchronous serial port, but time short distance transmission may use the parallel mouth and the synchronized serial port. Although the synchronized serial port the speed is low, but the holding wire are few, uses in the low speed low-power data transmission; The parallel mouth’s transmission speed is high, but the holding wire are many, uses in the high speed large capacity data transmission.
This article in general bidirectional and in mouth correspondence foundation, the reference many kinds of monolithic integrated circuit’s bus interfaces, proposed easy and feasible many machine and mouth agreement, realizes, between many monolithic integrated circuit’s high speed data correspondences. This agreement takes the holding wire to be few, simplicity of operator.
more than 1 machine and mouth communication protocol
Many machine and mouth agreement, had stipulated the data signal and the control signal, have realized 3 kind of main line operator schema, has defined the main line operation succession.
Many machine and mouth agreement, has defined SET, A/D, W/R, the D0~D7 altogether 11 holding wires. And: SET is reads in the control, the main engine either from machine along transmits in the drop the address or the data to bidirectional and mouth D0~D7; W/R is reads/writes the control, when W/R=0 expressed that the main engine reads from machine, when W/R=1 expressed that the main engine writes from machine; A/D is the address/data access control, when A/D=0 expresses the transmission data, when A/D=1 expresses the transport address; DO~D7 is the bidirectional data address main line, coordinates W/R and A/D carries on the address and the data two-way transmission. Through W/R and a/D control signal, has realized 3 kind of main line operator schema, like Table 1 arranges in order.
2 agreement monolithic integrated circuit simulations
Realizes and the mouth agreement when with the monolithic integrated circuit, main engine work in inquiry way, from machine work in interrupt mode, from machine the SET signal must receive from machine external interrupt pin.
Control position logical value definition:
#defincREAD O
#dcfine WRIT l
#define DATA O
#define ADDR 1
2.1 main engines and mouth agreement procedures
The main engine many machine and the mouth holding wire Yamagimachi use monolithic integrated circuit’s random 1 bidirectional and the mouth and random 3 I/O, the main engine in inquire under the way on own initiative with from machine the correspondence, to carries on from machine the data reads/writes. Through transfer time delay function delay(), causes the main engine and from machine realizes to the SPI transmission speed control. The user program only need transfer PPI_ReadBuf() and the PPI_WritBuf() function may to carry on from machine the data reads/writes.
2.2 from machine and mouth agreement procedure
A/D and W/R may use monolithic integrated circuit’s random I/O from machine many machine and the mouth holding wire, is DO~D7 assigns one bidirectional and the mouth, but SET must use the INT pin. This design has used the INTO pin. From machine many machine and the mouth agreement realizes in the interrupt service, coordinates the main engine in the interrupt to realize the data read-write agreement. In this example, the data saves in the buf buffer.
Conclusion
This article proposed and the mouth agreement has realized many machine correspondences which the monolithic integrated circuit asked that this procedure obtained the application in reality. This agreement may in include on the external interrupt monolithic integrated circuit to realize, may also use on CPLD realizing with monolithic integrated circuit’s correspondence. This method simple, reliable, the cost is low, has the high promoted value.
