Connection between SLE4520 and SABA8051

This chip was launched by Siemens of Germany in 1986 and is specially used for the control
of three-phase VVVF power supply . It uses ACMOS technology and adopts a standard 28-pin dual in-line package. This chip must be used in conjunction with an 8-bit microprocessor to generate a three -phase SPWM drive signal. SLE4520 can convert an 8-bit number sent by the microprocessor into a pulse of corresponding width. Figure 6 6 shows a connection between SLE4520 and SAB8051 microprocessor, for which Siemens has developed corresponding software. Of course, integration with other hardware and software is also possible.     1. The internal unit of SLE4520, SLE4520, integrates a crystal oscillator t as the oscillation source of the programmable frequency divider. It is also output to the outside of the chip through a buffer . There is no need to connect a capacitor to the end of the crystal oscillator.     The data from the SAB8051 microprocessor is transmitted from the PO port to the SLE4520 through ALE and WRej control, and is latched in three (phase) 8-bit latches , two 4-bit latches, and a 3-bit address latch decoder. middle. The SAB8051 microprocessor uses the instruction MOVX @RO, A to transmit data, in which the external address has been stored in the register RO, and the data to be transmitted is in the accumulator A. The address distribution of each latch is as follows:     Address latch     OOH A-phase 8-bit latch     OIH B-phase 8-bit latch     OZH C-phase 8-bit latch     03H Delay time control latch     04H Frequency divider control lock Registers The last two of the five latches mentioned above can only be written to during initialization. When the microprocessor outputs , the 3-bit address is latched and decoded on the falling edge of the ALE signal} and the data is loaded into the latch through the bus on the rising edge of the WR signal .