HT6513 Datasheet | Holtek Semiconductor

Features - - - - - Low power dissipation Use 32.768KHz crystal Crystal oscillator circuits on-chip 1200 baud rate serial output Power directly from RS-232C without external power supply - - - - Three key-switches and four photo-couples inputs Key-in and key-release debounce interval 52 ms The HT6513 can execute two different outputs with any of the key-switch inputs RXD with heavy NMOS output General Description The HT6513 is a specially designed CMOS IC for mouse control applications. Capable of driving up to 3 key-switches and 4 photo-couplers directly into a standard RS-232C line, and it can be operated without an external power supply. It is patible with both Microsoft and Mouse systems with false entries being prevented by internal debounce circuits. Pin Assignment 23rd Oct ’96 Block Diagram Pin Description Pin Name I/O Internal connection Description When this pin is connected to VDD, then HT6513 is assigned to operate under the microsoft mode only. If the pin is connected to VSS, then HT6513 will operate under the mouse system mode. If MS pin is “floating”, the HT6513 is on the power on initiation mode. For IC test only. The test pin must be connected to VSS, while the chip is under normal usage. Oscillator input pin Oscillator output pin The signal is sent by the mouse driver from the puter to select the mode. The HT6513 replies with the selected mode to the RXD line after the pulse signal of the RTS line. RXD will send out “CD”H code under the microsoft mode. There are 7 or 8 bits in each data byte. Using parallel-in and serial-out circuit, the data bytes are shifted out from bit 0 through the most significant bit. HT6513 will transmit the data when the status of the three key-switches or the state of the horizontal counter or vertical counter change. Negative power supply - TEST OSCI OSCO Pull-Low - - - RXD NMOS Open Drain - 2 23rd Oct ’96 Pin Name I/O Internal connection Description Three...