com81c17 Standard Microsystems Corp., com81c17 Datasheet
com81c17
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com81c17 Summary of contents
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... Character Length Bits - Stop Bit Selection ! Small 20 Pin DIP (300 mil) or PLCC ! Full or Half Duplex Operation The COM81C17 TPUART is an asynchronous only receiver/transmitter with programmable baud rate generator housed in a twenty pin package. The TPUART receives serial data streams and converts them into parallel data characters for the processor ...
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FEATURES ........................................................................................................................................ 1 GENERAL DESCRIPTION .................................................................................................................. 1 PIN CONFIGURATION/TYPICAL TPUART INTERFACE ..................................................................... 3 BLOCK DIAGRAM .............................................................................................................................. 4 DESCRIPTION OF PIN FUNCTIONS ................................................................................................. 5 FUNCTIONAL DESCRIPTION ............................................................................................................ 6 THE ON CHIP BAUD RATE GENERATOR ......................................................................................... 7 REGISTER DESCRIPTIONS .............................................................................................................. 8 OPERATIONAL ...
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... CLOCK nCS 3 nRD GND nWR GND Package 20 Pin DIP D0-D7 nCP1 nCP2 nCS COM81C17 RS TWENTY PIN TX nWR UART nRD nINT RX 3 Vcc nINT 13 CLOCK ...
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... WRITE nWR DECODE RS LOGIC MASK nINT REGISTER & LOGIC VCC CONTROL REGISTER GND FIGURE 2 – COM81C17 BLOCK DIAGRAM 1800 OHM 220 OHM 7404 220 OHM 30 pF FIGURE 2A – 5.0688 MHz CRYSTAL OSCILLATOR CIRCUIT TRANSMIT BUFFER TRANSMIT SHIFT REGISTER TRANSMIT MODE CONTROL ...
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DESCRIPTION OF PIN FUNCTIONS DIP PIN NO. NAME 1, 2, 5-7, DATA BUS 9,11-12 3 CHIP SELECT 4 READ DATA STROBE 8 WRITE DATA STROBE 10 GROUND 13 CLOCK 14 INTERRUPT REQUEST 15 REGISTER SELECT 16 RECEIVER DATA 17 TRANSMITTER ...
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FUNCTIONAL DESCRIPTION RESETTING THE TPUART The TPUART must be reset on power up. Since there is no external pin allocated for hardware reset, this is accomplished by writing a One (HIGH) followed by writing a Zero (LOW) to the Command ...
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THE ON CHIP BAUD RATE GENERATOR The TPUART incorporates an on chip Baud Rate Generator that can be programmed to generate sixteen of the most popular baud rates. The TPUART also allows the bypassing of the Baud Rate Generator by ...
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... Table 3 - COM81C17 Mode Register Description (Bits BIT 0 CP1 - The Mode Register bit 0 determines whether the CP1 pin will be configured to provide the function of CTS or will serve as a general purpose 1 bit input port. In either case, its state will be reflected in Status Register bit 0. ...
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... Table 4 - COM81C17 Status Registers Description (Bits 0-7) BIT 0 CP1 - This reflects the inverted state of the control pin CP1. 1 CP2 - This is active only when the nCP2 pin is programmed input set by its corresponding input pin and reflects the inverted state of the control pin nCP2. When the CP2 pin is programmed as an output, this bit is forced to a zero ...
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... A) Reading the Receive Buffer Register B) Asserting the RECEIVER RESET bit in the Control Register C) Asserting internal reset Table 5 – COM81C17 CONTROL REGISTER DESCRIPTION (BITS 0-7) BIT 0 Not used (test mode bit, must be zero). 1 CP2 – This bit controls the nCP2 output pin. compliment of the register data. When the CP2 bit is set, the nCP2 pin is forced low. ...
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INTERRUPT MASK REGISTER DESCRIPTION This is an eight bit write only register which is loaded by the processor. These bits are used to enable interrupts from the corresponding bits in the Status Register. This register is reset with internal reset. ...
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OPERATIONAL DESCRIPTION MAXIMUM GUARANTEED RATINGS* Operating Temperature Range ......................................................................................... 0 Storage Temperature Range .......................................................................................... -55 Lead Temperature Range (soldering, 10 seconds) .................................................................... +325 Positive Voltage on any pin ..................................................................................................... V Negative Voltage on any pin, with respect to ground ................................................................... ...
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Table CHARACTERISTICS SYMBOL WRITE CYCLE t nCS nWR 1 t nCS, RS hold time to nWR 2 t nWR pulse width 3 t Data BUS in setup time to nWR 4 t Data BUS in ...
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nWR D IN FIGURE 3 – PROCESSOR TO TPUART WRITE CYCLE nCS nRD D OUT FIGURE 4 – PROCESSOR FROM TPUART READ CYCLE ...
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TO CONTROL REGISTER D 7IN INTERNAL RESET FIGURE 5 – INTERNAL RESET TIMING nCP1 nCP2 nINT FIGURE 6 – nCP1 TRANSITION TO nINT ...
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FIGURE 7 – nCP2 OUTPUT TIMING nCP1 nCP2 FIGURE 8 – nCP1, nCP2 INPUT TIMING ...
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STANDARD MICROSYSTEMS CORP. Circuit diagrams utilizing SMSC products are included as a means of illustrating typical applications; consequently complete information sufficient for construction purposes is not necessarily given. The information has been carefully checked and is believed to ...