HT6513 Mouse Controller 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 can be operated without an external power supply. It is compatible with both Microsoft and Mouse systems with false entries being prevented by internal debounce circuits. 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 Pin Assignment 1 23rd Oct ’96 HT6513 Block Diagram Pin Description Pin Name I/O Internal connection Description MS I — 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. TEST I Pull-Low For IC test only. The test pin must be connected to VSS, while the chip is under normal usage. OSCI I — Oscillator input pin OSCO O — Oscillator output pin — The signal is sent by the mouse driver from the computer 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. RTS I RXD O NMOS Open Drain VSS I — Negative power supply 2 23rd Oct ’96 HT6513 Pin Name R M L I/O I Internal connection Description Pull-Low Three key-switches have seven different combinations in total. Both key-pressed and key-released signals will be sent accompanied with horizontal and vertical state. The status of the key-switches, the values of horizontal or vertical counters will be present at RXD and RXD. The debounce interval for both key-press and key-release is 13ms. X1 X2 Y1 Y2 I — Four photo-couplers signals denote UP, DOWN, LEFT, and RIGHT state. During the scaning period, as long as the photo-couplers change their states, the value of vertical or horizontal counter will increase or decrease accordingly. VDD I — Position power supply Approximate Internal connection circuits 3 23rd Oct ’96 HT6513 X1/X2/Y1/Y2 Input pin I/V curve (optomechanical mouse) Absolute Maximum Ratings Supply Voltage ................................. –0.3V to 7V Storage Temperature................. –50°C to 125°C Input Voltage.................... VSS–0.3V to VDD+0.3 Operating Temperature............... –20°C to 75°C D.C. Characteristics Symbol Parameter (Ta=25°C) Test condition VDD Condition — Min. Typ. Max. Unit 4.0 5.1 6.1 V — 400 760 µA VDD Operating voltage — IDD Operating current 5.6V VIL X1,X2,Y1,Y2 Input low voltage 5.6V — 0 — 1.1 V VIH X1,X2,Y1,Y2 Input high voltage 5.6V — 1.8 — 5.6 V VIL1 Input low voltage, other pin 5.6V — 0 — 1 V VIH1 Input high voltage, other pin 5.6V — 3.5 — 5.6 V IOL RXD output sink current 5.6V 3.5 6 — mA VOH RXD high-level output voltage — — 16 V RPL Pull-low resistance 65 — 200 KΩ — 5.6V 4 No load VOL=0.56V — L, M, R key-switches 23rd Oct ’96 HT6513 A.C. Characteristics Symbol Parameter (Ta=25°C) Test Condition VDD Condition Min. Typ. Max. Unit 30.8 32.768 34.2 KHz fSYS System Clock 5.6V Crystal Oscillator fP Photo-Couple input frequency 5.6V — — — 8.2 KHz fN Photo-Couple operation frequency 5.6V — 0 — 8 KHz tKD Key debounce 5.6V — — 52 — ms tMS Transmission time 5.6V mouse system (1200 bps) — 41.3 — ms tMI Transmission time 5.6V microsoft (1200 bps) — 24.8 — ms tS Start bit time 5.6V (1200 bps) — 0.85 — ms tD Data bit time 5.6V (1200 bps) — 0.82 — ms tP Stop bit time 5.6V (1200 bps) — 0.82 — ms tRD Mode code delay Time (fSYS=32.768KHz) 5.6V (1200 bps) 11.9 — 14 ms tR Rising edge crossed width 5.6V — 31 — — µs tF Falling edge crossed width 5.6V — 31 — — µs 5 23rd Oct ’96 HT6513 Function Descriptions spond to key switch-status, horizontal counter and vertical counter respectively. The autospeed sensing circuits ensure detection of higher mouse speeds resulting in the use of the 4th and 5th words for extra horizontal and vertical overflow counts respectively. For lower mouse speeds the 4th and 5th words remain at zero. Mouse system mode Any change of state of the mouse key-switches or photo-couplers will be detected by the HT6513 and transmitted over the RS-232C. The mouse system protocol will send five words at a 1200 baud rate with each word containing 10 bits, one start bit, one stop bit and eight data bits. The first, second and third words correOutput word format: Mouse system word structures Bit No. 7 6 5 4 3 2 1 0 1st word 1 0 0 0 0 L’ M’ R’ 2nd word H7 H6 H5 H4 H3 H2 H1 H0 3rd word V7 V6 V5 V4 V3 V2 V1 V0 4th word EH7 EH6 EH5 EH4 EH3 EH2 EH1 EH0 5th word EV7 EV6 EV5 EV4 EV3 EV2 EV1 EV0 ’: denotes complement H0~H7: The values of horizontal counter. V0~V7: The values of vertical counter. EH0~EH7: The values of extra horizontal counter. EV0~EV7: The values of extra vertical counter. Microsoft system mode Output word format: In the microsoft mode only 3 words are transmitted with each word divided into one start bit, seven data bits and two stop bits. Note that only 2 switch operation is available with the “M” switch being redundant in this mode. The “L” and “R” switch status together with the two most significant bits of both vertical and horizontal counters are transferred in this first word. The second and third word represent the horizontal and vertical counters respectively. Note that this vertical data is recorded in 2’s complement format. Bit No. 6 Mouse system word structures 6 5 4 3 2 1 0 1st word 1 L R V7’ V6’ H7 H6 2nd word 0 H5 H4 H3 H1 H0 3rd word 0 V5’ V4’ V3’ V2’ V1’ V0’ H2 23rd Oct ’96 HT6513 Timing Diagrams 7 23rd Oct ’96 HT6513 Application Circuit RXD output 8 23rd Oct ’96