19-0141; Rev. 1; 1/96 MAX186 Evaluation System/Evaluation Kit ___________________________Features The MAX186 evaluation system (EV system) consists of a MAX186 evaluation kit (EV kit) connected to a Maxim 80C32 microcontroller (µC) module. The unit connects to an IBM-compatible personal computer running software provided with the MAX186 EV kit. Both boards come fully assembled and tested. ♦ Includes EV Kit and 80C32 µC Module Using the EV system, the MAX186 input multiplexer can be software-configured in a variety of single-ended or differential modes with unipolar or bipolar input ranges. The MAX186 can be evaluated with a VSS voltage of 0V or -5V, selectable from the personal computer’s keyboard. ♦ Internal Reference Voltage The EV system is also useful for evaluating the MAX186’s shutdown feature. The MAX186 can be operated in three states of readiness between conversions. There are provisions for monitoring the supply current in the different shutdown states, and for varying the delay between conversions. ♦ Proven PC Board Layout Order the EV system (MAX186EVSYS-DIP) for comprehensive evaluation of the MAX186 or MAX188 using a personal computer. Order the EV kit (MAX186EVKIT-DIP) if the 80C32 module (80C32MODULE-DIP) has already been purchased with a previous Maxim EV system, or for custom use in other µC-based systems. The MAX186 EV kit can also perform limited evaluation on a stand-alone basis (see the MAX186 EV Kit Quick Start section). ♦ 12-Bit Resolution ADC ♦ Serial µC Interface ♦ Unipolar +4.096V or Bipolar -2.048V to +2.048V Input Ranges ♦ Low Supply-Current Shutdown Mode ♦ Source Codes for All Software Provided ♦ Evaluates All Operating Modes ♦ Prototyping Area Provided ♦ Digitizes 8 Analog Inputs ♦ Fully Assembled and Tested ______________Ordering Information TEMP. RANGE BOARD TYPE MAX186EVSYS-DIP PART 0°C to +70°C Through-Hole MAX186EVKIT-DIP 0°C to +70°C Through-Hole 80C32MODULE-DIP 0°C to +70°C Through-Hole ___________________________________________________________________EV System ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 Evaluates: MAX186 _______________General Description Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit _______EV System Component List QTY 1 1 DESCRIPTION MAX186 evaluation kit (MAX186EVKIT-DIP) 80C32 µC module (80C32MODULE-DIP) ___MAX186 EV System Quick Start The MAX186 EV system includes a Maxim 80C32 module and a MAX186 EV kit. The two connect through a 40-pin data connector on adjoining edges of the boards. The EV system then connects to an IBM-compatible computer running software provided with the MAX186 EV kit. The personal computer and the 80C32 module are connected via a standard RS-232 serial communication port. If the serial port on the personal computer has the standard 9-pin connector, a straight through cable is used to attach the board. Systems with a 25-pin serial port connector need an adapter or adapter cable (D25 female to D9 male). Both the adapter and the cable are available at most computer supply stores. The steps for using the MAX186 EV system are outlined as follows: 1. Copy the MAX186 software disk to another disk or to a hard-disk directory in the personal computer. Store the original disk in a safe location. 2. Read the README text file found on the floppy disk. It contains information on any changes to the hardware or software introduced after this manual was written. 3. Connect the MAX186 evaluation board to the 40-pin data connector on the Maxim 80C32 module. 4. Connect an 8V to 16V source to the 2-pin power connector on the 80C32 module. The positive lead connects to the terminal marked VIN. 5. Connect a cable from the personal computer serial connector to the 9-pin RS-232 connector on the 80C32 module. 6. Turn on the power to the 80C32 module. The switch is located on one edge of the board. The LED indicates power from the on-board regulator. 7. To start the Maxim EV system software on the personal computer, set the default drive or directory to match the storage location of the Maxim programs, and then enter the program name “186EVKIT”. 2 ____________EV Kit Component List DESIGNATION C1, C2, C3, C4, C8 QTY C6* 1 5 DESCRIPTION 10µF 16V radial electrolytic capacitors 22µF low-ESR radial electrolytic capacitor C5, C7, C9, C10 C11-C18 R1-R8 R9* U1 U2 U3 J1 None H1 None None 4 0.1µF ceramic capacitors 8 8 1 1 1 1 1 1 1 1 4 None 1 None None 1 1 0.01µF ceramic capacitors 300Ω 5% resistors 10kΩ 9-resistor SIP Maxim MAX186DCPP Maxim ICL7660CPA Maxim DG413DJ Female 40-pin data connector 20-pin IC socket for U1 8-pin header 3.00" x 3.75" PC board Rubber feet MAX186 EV kit software on a 5 1/4" floppy disk MAX186 data sheet MAX186 EV kit manual *C6 and R9 are supplied with the kit but not mounted on the printed circuit board. 8. Review the complete list of available commands, found in the menu at the bottom of the screen. Descriptions of the commands also appear later in this manual. 9. Set the active serial port, shown on the bottom line, to indicate the port connected to the Maxim 80C32 module. The control-T command toggles the active port between COM1 and COM2. 10. The 80C32 will transmit a logon message and RAM test results when communications are initialized. The MAX186 RAM resident program will then be automatically downloaded. The system is ready for use when the MAX186 revision banner appears and the status indication on the bottom line changes to "****READY****". 11. Connect the analog inputs to the CH0-CH7 pads and refer to the menu at the bottom of the screen for commands to configure the input multiplexer. 12. Single conversion cycles occur whenever the Enter key is pressed. Continuous conversion cycles are initiated with a “C” and continue until any key is pressed. _______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Table 1. Port 1 Bit Functions This section applies only to use of the MAX186EVKITDIP without the 80C32 module. BIT NAME The MAX186 evaluation board can easily be configured in the quick-look circuit of Figure 5 of the MAX186/MAX188 data sheet. All of the necessary digital pins are provided on the 8-pin header located along the bottom edge of the board. Each pin function is indicated by labels below the header. P1.0 VSS SEL P1.1 SCLK Serial clock for data transfer P1.2 SHDN Drives the MAX186 SHDN pin. Cut jumper JU2 to float the SHDN pin. P1.3 – 1. Solder the 10-pin SIP resistor, provided with the kit, in the R9 location on the EV kit board. The SIP resistors act as pull-ups for the digital signals connected to the 8-pin header. The marked end of R9 is pin 1. 2. Connect +5V and ground (GND) to the appropriately labeled pads on the evaluation board. 3. To operate the MAX186 in single-supply mode, ground the header pin marked VSEL. Leaving the pin open sets the MAX186 VSS pin to -5V (dual-supply operation). 4. Connect a clock signal (0.1MHz to 0.4MHz*) to the header pin, labeled SCLK. FUNCTION VSS select switches the MAX186 VSS pin between ground and -5V. Logic low, VSS = 0V; logic high, VSS = -5V. Not used P1.4 SSTRB MAX186 SSTRB pin. Provides the busy output during internal clock mode (see MAX186/MAX188 data sheet). P1.5 DOUT MAX186 DOUT pin. Transfers conversion data from the MAX186 to the 80C32. P1.6 CS MAX186 CS pin. Enables serial communications with the MAX186. P1.7 DIN MAX186 DIN pin. Transfers data from the 80C32 to the MAX186. 5. Ground the header pin, labeled CS. 6. Connect an analog input source to the channel 7 input pad, labeled CH7. 7. Connect an oscilloscope, as shown in Figure 5 of the MAX186/MAX188 data sheet. * To run at clock frequencies up to 2MHz, an external compensation capacitor must be connected to the VREF pin. Install the 22µF capacitor supplied with the kit in location C6, and cut the trace across jumper JU2 to disable the MAX186 internal compensation. _______________Detailed Description VSS Circuit An ICL7660 +5V to -5V converter and a DG413 analog switch (mounted on the MAX186 evaluation board) provide the means to switch the MAX186’s V SS voltage between ground and -5V. The analog switch is not required for most application circuits because the VSS voltage will be fixed at either -5V or ground. A negative VSS supply is required only when the MAX186’s input is expected to go below ground. The ICL7660 provides a -5V source with minimal additional circuitry. The ICL7660 converter circuit on the MAX186 EV kit is the standard circuit for +5V to -5V conversion. Its 10mA output capacity is much more than is needed by the MAX186, which requires only 50µA. The additional current is available for user circuits in the prototyping area. For applications where the MAX186 is the only load, the 10µF capacitors may be reduced to 0.1µF. Serial Interface The 80C32 and MAX186 communicate through the 8 bits of port 1 on the 80C32. Table 1 lists the function of each bit. The 80C32 drives MAX186 input data on the DIN bit and receives data from the MAX186 on the DOUT bit. For the first eight clock cycles after chipselect ( CS ) goes low, DIN data is clocked into the MAX186 on the rising edge of the serial clock (SCLK) signal. For the 12 data-output clock cycles, the MAX186 updates DOUT data on the falling edge of SCLK. See the MAX186 data sheet for complete information concerning the serial interface; Figures 6-12 of the MAX186/MAX188 data sheet are timing diagrams _______________________________________________________________________________________ 3 Evaluates: MAX186 _______MAX186 EV Kit Quick Start Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit for operating in the internal and external clock modes. Note that the maximum conversion rate of the EV system is limited to 5ksps, because of the speed limitation of the 80C32. For evaluation at full speed, see the MAX186 EV Kit Quick Start section. The MAX186 digital signals are available on the 8-pin header located on the bottom edge of the board. This header provides convenient connections for scope probes or a ribbon cable. Digital timing can be observed on these pins when the “loop continuously” command (“L”) has been entered. Conversion Cycles The MAX186 performs conversions on demand or at preset intervals. The conversion sequence does not vary with the two methods. If the device is in shutdown mode, a dummy conversion brings it out of shutdown, and the program delays to allow the reference voltage to settle. Then, as many as eight conversions are performed to collect data for a complete line of the screen display. Finally, if shutdown mode is enabled, another dummy conversion returns the MAX186 to the proper shutdown state. When conversion cycles are repeated at regular intervals, using the load RAM (R) or loop continuously (L) commands, a programmable delay occurs between the groups of conversions. The “N” command can be used to vary this shutdown period. The interval can be observed with a scope connected to the CS pin (available on the 8-pin header) after entering the “L” command. Shutdown Mode The MAX186 has two shutdown levels. The FULL shutdown mode completely disables the MAX186 reference circuit and reduces supply current to 2µA. A delay of 300µs is required to activate from this shutdown state. The delay must be greater when the external reference compensation capacitor, C6, is installed. Be sure to set the reference settling delay (using the “Q” command) whenever the FULL shutdown mode is used. Table 5 of the MAX186/MAX188 data sheet lists the reference settling times required for different external capacitors. The second shutdown level disables only the reference output buffer. This drops the supply current to 30µA, but requires a shorter delay (5µs with internal compen- 4 sation) between activation and conversion cycles. This is referred to as the FAST shutdown mode. On the MAX186 evaluation board, the SHDN pin (P1.2), is programmed high so that it always enables the MAX186 in normal operation. All modes are controlled through software. In FAST or FULL shutdown mode, the MAX186 is placed in shutdown between conversion cycles and activated just before the conversions begin. This reduces the average supply current but will require a delay before the conversions. The MAX186EVKIT Personal Computer Program section has information on varying the delay and controlling the shutdown mode. Jumper JU2 is in series with the SHDN pin of the MAX186. Opening this jumper floats the SHDN pin, disabling the internal compensation of the reference buffer. The external compensation capacitor, C6, is supplied with the kit but not mounted on the printed circuit board. If you wish to use external compensation, cut the trace across JU2 and mount the 22µF capacitor, C6. The reference settling delay must be increased. See the MAX186/MAX188 data sheet for descriptions of internal and external reference compensation. Evaluating External Reference Voltages The MAX186 can be operated with an external reference voltage if the internal reference is disabled. Connecting the REFADJ pin to V DD will disable the internal reference. Soldering a short piece of wire across jumper JU3 will make this connection. The 22µF capacitor should also be soldered into location C6 when using an external voltage. The reference voltage is then applied to the pad labeled VREF. To use the MAX188, which requires an external reference, install C6 and connect the reference source to the VREF pad. Jumper JU1 facilitates monitoring the MAX186 supply current in the shutdown modes. The jumper allows the insertion of a current meter in series with the MAX186 VDD supply. To monitor the current, cut the printed circuit trace between the two holes marked JU1. Then solder two short leads in each hole and connect the ammeter. A short piece of wire can be soldered across the jumper location to restore normal connections. _______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit V SS supply voltage (GND or -5V), operating mode (active, FAST shutdown, or FULL shutdown), and reference voltage. The next three lines indicate the configuration of the input multiplexer. This part of the display changes whenever a command alters the configuration of the MAX186. Analog Inputs Lines 6-20 of the display are for conversion results. Readings from the MAX186 appear in columns across the screen. This field scrolls as new readings are collected. Each of the eight inputs has a 300Ω resistor in series. These optional resistors were included as current-limiting devices for input overvoltage conditions. There is also an optional 0.01µF capacitor on each of the inputs. This provides the low source impedance required when the channel is the low side of a differential input pair. The input capacitors are not required on channels used as single-ended inputs. Refer to the Pseudo-Differential Input section of the data sheet. Reference Adjustment The MAX186 software assumes a reference voltage of 4.096V. This value is used for calculating the displayed results after each conversion. The value can be altered to reflect the exact reference voltage of the MAX186 or to scale the displayed readings. Changing the indicated value does not alter the MAX186’s reference voltage. Use the “F” command to enter the new reference value. The MAX186’s internal 4.096V reference voltage can be adjusted over a ±1.5% range by adding resistors R10 through R13, shown on the schematic. Refer to the MAX186 data sheet for detailed information about the reference voltage. ___________________________Software 186EVKIT Personal Computer Program The 186EVKIT program is one of two separate programs supplied with the MAX186 EV kit. The program, which runs on a personal computer, handles the user interface, controls communications with the 80C32 module, and displays conversion results. It was written in the C language using Microsoft’s QuickC software package. The output display consists of several fields. The top five lines of the screen contain three separate elements. The top line displays the title and version. The next four lines show the MAX186 configuration. On line 2, indicators show the clock mode (internal or external), The bottom part of the display contains a menu of the available commands. Type “M” to examine the complete list of commands. The bottom line displays the status of the communications port connected to the Maxim 80C32 module. The communication status indications in the lower righthand corner of the display will read "****Not Ready****" until the RAM resident program has been downloaded. It then changes to “*** READY ***”. Other status flags appear here when the MAX186 conversions are being stored in RAM or retrieved for display. Also shown on the bottom line is the present selected channel. All commands referring to the input multiplexer affect only the indicated selected channel. The top portion of the display updates whenever a channel command is entered. ____________RAM Resident Program The 186RAM.MAX program is an 80C32 program that is transferred from disk to the static RAM on the 80C32 module. It receives conversion commands from the 186EVKIT program running on the personal computer, controls the conversion cycle, and returns the results. Its operation is transparent to the user. _________EPROM Resident Program In addition to the two programs supplied with the MAX186 EV kit, a small 80C32 bootstrap program is stored in the EPROM located on the 80C32 board. The EPROM resident program initializes the 80C32, establishes communications over the RS-232 link, checks the static RAM, and downloads the 186RAM program. Its operation starts on power-up and whenever the reset button is pressed. It transmits an identification banner after receiving the first character and then tests the onboard static RAM. _______________________________________________________________________________________ 5 Evaluates: MAX186 The loop command (L) continuously cycles the MAX186 using the delays set by the user for the time between conversions and the reference settling delay. The mode is useful for observing timing relationships as well as monitoring the supply current with different delays and shutdown levels. Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit The last operation performed by the EPROM resident program is downloading the 186RAM program and storing it in the static RAM. Once the program is fully loaded, control of the 80C32 is transferred to the RAM resident 186RAM program. Both the EPROM and RAM resident programs were written with an assembler from Avocet Systems (Phone: 1-800-448-8500). Source code for all Maxim software can be found on the floppy disk supplied with the MAX186 EV kit. Available Software Commands The following is a list of the keyboard commands available in the 186EVKIT program. A copy of this section is on the floppy disk provided with the MAX186 evaluation board. The SOFTWARE.DOC file will contain any updates or revisions made after this manual was printed. 0-7 ..........Set the selected channel for the commands affecting the input multiplexer configuration. The selected channel is displayed on the bottom display line. CR ..........A carriage return (CR) will perform a single conversion cycle and display the results. C ............Starts a continuous stream of conversions. Pressing any key will terminate the stream. I ..............Sets the number of conversion cycles to be collected in RAM when the “R” command is given. The range is between 1 and 1024. Two bytes are collected for each reading stored. With all eight channels active and 1024 cycles collected, the RAM would hold 2 x 8 x 1024 (16k) bytes. N.............Sets the delay between conversions for the looping and the RAM collection sequence. The interval increases approximately 2µs for each loop. Q .............Changes the reference settling delay (the interval between bringing the MAX186 out of shutdown and the start of conversions). The interval increases approximately 2µs for each loop. S .............Sets the selected channel to single-ended mode. R .............Starts the collection of data to RAM. The status line will display “*** CONVERTING ***” while the data is being collected in the static RAM. The number of conversions collected is set with the “I” command. Pressing any key will terminate the collection. D...........Sets the selected channel to differential mode. The selected channel becomes the analog high (+) input. Channel pairs 0/1, 2/3, 4/5 and 6/7 can operate in combinations of single-ended inputs and differential pairs. For differential pairs, the first channel listed on the top information bar is the positive input. The output reading will be positive when this pin is more positive than the other input. E .............Uploads the data from the RAM and displays the values. The status line will display “*** UPLOADING ***” while the data is being received over the serial data link. Consider setting the baud rate higher than the default 1200 if this feature is used frequently. After the data has been uploaded, the following commands may be used to examine different entries: O ...........Toggles the selected channel off/on. The selected channel is also turned on when any command alters its mode. Up Arrow ............Move 1 entry up Down Arrow ........Move 1 entry down Page Up .............Move 12 entries up Page Down .........Move 12 entries down. U .............Sets the selected channel to unipolar mode. B .............Sets the selected channel to bipolar mode. H ...........Sets the data output format to hexadecimal mode. The output will range between 0-FFF for 0 to +4.096V in unipolar mode, and between 8007FF for -2.048V to +2.048V in bipolar mode. V ...........Sets the data output format to decimal mode. The display will range between 0.000V and +4.096V in unipolar mode, and between -2.048V to +2.048V in bipolar mode. 6 Pressing any other key will return to normal operation. M.............Displays another portion of the help menu at the bottom of the screen. All commands are available at all times. Esc..........Clears the data field and redraws the display. _______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Ctrl-R ......Changes the baud rate of the active serial port. The board and program initialize at 1200. If the program is exited with another rate active, the board must be manually reset. Higher baud rates are usable for data uploading and on personal computers with faster video operations. If the rate is set too high, data will be lost. Ctrl-U ......Downloads the RAM resident program. Ctrl-X.......Exits the program and returns to DOS. F .............Enters the measured value for the reference voltage. This value is used in the calculation for the displayed conversion results. The present value is on the second line of the display. K .............Toggles the MAX186 clocking mode between internal and external modes. The present mode is indicated on the second line of the display. Z ...........Toggles the MAX186 V SS supply voltage between ground and -5V. The present voltage is indicated on the second line of the display. P .............Toggles the MAX186 state between conversion cycles. In Power-On, the MAX186 reference circuit is always ready. In FAST Shutdown, the MAX186’s reference output buffer is disabled and the MAX186 draws approximately 35µA between conversion cycles. In FULL Shutdown, the MAX186 reference circuit is completely shut down and supply current drops to approximately 5µA between conversion cycles. _______________________________________________________________________________________ 7 Evaluates: MAX186 Ctrl-T ......Toggles the active serial communications port between COM1 and COM2. The active port is identified on the bottom status line. 8 11 DG413 S1A VSS 27 8 3 16 2 7 6 DG413 S1D 15 14 DG413 S1B 1 JU2 2 3 DG413 S1C C1 10µF EXT VSS C5 0.1µF 9 10 P1.0 +5V 1k 1k 1k 1k 1k 1k 1k 1k 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF 0.1µF SHDN 29 R1 R2 R3 R4 R5 R6 R7 R8 C18 C17 C16 C15 C14 C13 C12 C11 P1.2 CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 5 6 7 8 9 10 1 2 3 4 1 8 N.C. V+ 2 7 CAP+ OSC 3 6 GND LV 4 5 CAP- VOUT ICL7660 U2 MAX186 U1 CH0 VDD CH1 SCLK CH2 CS CH3 DIN CH4 SSTRB CH5 DOUT CH6 DGND CH7 AGND VSS REFADJ SHDN VREF +5V 16 15 14 13 12 11 20 19 18 17 -5V C10 0.01µF C6 10µF C7 0.1µF JU3 5 6 R12 15k R10 5k R13 11k 7 8 10k SIP RESISTOR C9 0.1µF 4 7 +5V C8 10µF C3 10µF C2 10µF JU1 8 +5V R11 100k 87654321 REFADJ VREF H1 28 33 34 31 32 GND 4 GND 3 GND 2 GND 1 SSTRB P1.4 DOUT P1.5 SCLK P1.1 CS P1.6 DIN P1.7 CS Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit C4 10µF Figure 1. MAX186 EV Kit Schematic _______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Evaluates: MAX186 Figure 2. MAX186 EV Kit Component Placement Guide _______________________________________________________________________________________ 9 Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit Figure 3. MAX186 EV Kit Component-Side Layout 10 ______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Evaluates: MAX186 Figure 4. MAX186 EV Kit Solder-Side Layout ______________________________________________________________________________________ 11 Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit ______________________80C32 Module 80C32 Module General Description The Maxim 80C32 microcontroller (µC) module is intended for use with this and other Maxim evaluation kits (EV kits). It contains the 80C32 µC, RS-232 interface, 8kbytes of EPROM, 32kbytes of static RAM, and address decoding logic. A 40-pin connector mates with a connector found on Maxim EV kits designed to interface with the 80C32 module. ____80C32 Module Component List DESIGNATION C1, C2 C4, C5, C6, C7, C8, C9, C10, C11, C12 QTY 2 C3, C13, C14 3 D1 J1 J2 R1 RS1 SW1 SW2 IC1 IC2 IC3 IC4 IC5 IC6 IC7 IC8 IC9 IC10 Y1 None 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 None 1 None None 4 1 12 9 DESCRIPTION 15pF ceramic capacitors 0.1µF, 50V ceramic capacitors 22µF, 16V radial electrolytic capacitors 1N4001 diode 40-pin right-angle male connector DB9 right-angle socket 620Ω resistor 10kΩ 10-pin, 9-resistor SIP Power switch Reset switch 80C32 MAX233CPP 27C64 74HCT573 74HCT139 74HCT08 74HCT245 62256 78M05 MAX707CPA 11.059MHz crystal 2-pin power connector 28-pin 600-mil socket for IC3 (the EPROM) Rubber feet 3.00" x 5.50" PC board The module is connected to an IBM-compatible personal computer over a serial communications port. Software provided with each EV kit runs on the computer and controls the unit consisting of the 80C32 module and EV kit. The program uses a routine stored in the 27C64 EPROM to download special 80C32 code for each kit. The downloaded code controls the EV kit and, together with the program running on the personal computer, displays the output data. The board operates from a single 8V to 22V supply. Both the pre-regulated and regulated +5V levels are available to the EV kit through the 40-pin connector. 80C32 Module Power Supply The Maxim 80C32 module requires an input of 8V to 22V for normal operation. An on-board 78M05 power regulator supplies the 5V required for the logic on the module, and any 5V requirements for the EV kit attached to the 40-pin connector. The pre-regulated voltage is also available on the data connector. The source must be capable of supplying 100mA for the module and meeting the load requirements of the EV kit. Microprocessor Supervisor A MAX707 on the module monitors the 5V logic supply, generates the power-on reset, and produces a reset pulse whenever the reset button is pressed. A watchdog function was not included because they frequently interfere while debugging programs, and debugging is a prime function of this board. 80C32 Microcontroller The 80C32 is a member of the popular Intel 8051 family of µCs. It is a low-power CMOS version that requires external ROM for program storage, 256 bytes of internal RAM, and four 8-bit I/O ports. Three of the ports are required by the system for serial communications and memory control. The fourth port (P1) is available through the data connector. The 80C32 communicates with the PC over a serial RS232 link. A MAX233 acts as a level shifter between the ±15V RS-232 signals and the TTL levels of the 80C32. ______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Port 0 (pins 32-39) of the 80C32 multiplexes the lower eight bits of memory address and the eight bits of read/write data. The lower eight bits of address data are latched during each I/O cycle by the 74HCT573 octal latch. The latch is controlled by the address latch enable (ALE) signal of the 80C32. Port 2 (pins 21-28) of the 80C32 supplies the upper eight bits of address information. The port 3 pins (10-17) provide several unrelated functions. Pins 10 and 11 are used as the receive data (RxD) and transmit data (TxD) pins of the RS-232 link. Pins 16 and 17 act as the write (WR) and read (RD) control signals for the data I/O cycles. Four other pins are configured as interrupt and timer controls, but are not used on this board. Memory The board has a 27C64 EPROM containing code for initializing the 80C32 and downloading additional program code to the 62256 RAM. After a reset, the EPROM resident code initializes the 80C32, determines the address range of the RAM, sets the RS-232 baud rate to 1200, and waits for communications from the PC. Receiving any character will prompt the program to send an initial banner that includes the program name, revision level, and boundaries of the on-board RAM. The 62256 CMOS (32kbyte) static RAM is used to hold program code for the various Maxim EV kits that use the 80C32 module as the controller. Programs are transferred from disk to the RAM using software running on a personal computer, such as MAXLOAD or other programs provided with Maxim EV kits. Programs written to execute from this RAM start at 4000 (HEX) and are typically less than 4kbytes long. The remaining RAM is available for data storage. Address Ranges Logic on the module board generates various enable signals for different address ranges. The ROM and RAM enable signals are fed directly to the respective chips. Several additional signals (CS0-CS3) are available on the data connector to be used by Maxim EV kits. Table 1 outlines the address range for each of the elements found on the 80C32 module. Table 1. Address Ranges in Hexadecimal ADDRESS RANGE (HEX) 0000 4000 C000 D000 E000 F000 ➔ ➔ ➔ ➔ ➔ ➔ ENABLE SIGNAL 3FFF BFFF CFFF DFFF EFFF FFFF ROM RAM CS0 CS1 CS2 CS3 Data I/O Connector A 40-pin connector mounted on the edge of the printed circuit board provides connection between the µC module and other Maxim EV kits. Both power and digital signals are transferred via the connector. To join the module board with an EV kit, carefully align and insert the pins on the connector with the mating 40-pin female connector of the kit. The pin functions are listed in Table 2. Table 2. I/O Connector Pin Functions PIN 1-4 5, 6 7, 8 9 10 11 12 13 14 15-18 19-26 27-34 35-40 FUNCTION Ground Pre-regulator input Regulated +5V RD WR CS0 CS1 CS2 CS3 ADDR0-ADDR3 DB0-DB7 P1.0-P1.7 Reserved DESCRIPTION Read strobe Write strobe Address C000-CFFF Address D000-DFFF Address E000-EFFF Address F000-FFFF Lowest 4 bits of address 8-bit data bus 8 bits of port 1 ______________________________________________________________________________________ 13 Evaluates: MAX186 The MAX233 also generates the output voltages necessary to drive RS-232 lines. Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit Software Architecture Software for EV kits using the Maxim 80C32 module is divided into three elements: the interface program running on an IBM-compatible PC, a module program located in EPROM, and a program supplied on disk that is transferred to the RAM located on the module. EPROM Resident Program The EPROM resident program initializes the 80C32, establishes communications over the RS-232 link, verifies the static RAM, and downloads other programs. Its operation starts on power-up and whenever the reset button is pressed. After reset, the program waits indefinitely to receive a character over the RS-232 port. When the first character is received, a logon banner identifying the module and firmware revision is transmitted. 14 Immediately following transmission of the logon banner, the program runs a checker routine for the on-board 256kbit static RAM. The RAM is filled with several patterns and then read to verify that each pattern has been retained. A pass or fail indication is displayed on the personal computer after each pass. EV kit software requires proper operation of the RAM. Do not attempt to use the board if any of the RAM checks fail. Two other programs for the EV kits are provided on a floppy disk shipped with each kit. One program acts as the user interface and transmits commands to the 80C32 module. The other is an 80C32 application program that executes from the RAM located on the module. The procedure for loading the programs varies with each kit, so follow the instructions provided. ______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Evaluates: MAX186 Figure 5. 80C32 Module Component Placement Guide (x2) ______________________________________________________________________________________ 15 Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit 34 P1.0-P1.7 27-34 ALL D9 MNEMONICS REFER TO THE HOST (DTE) 5 GND 1 DCD 4 DTR 6 DSR 27 2 TXD 3 RXD 7 RTS 8 CTS MAX233A U2 +5V 2 +5V 5 T1 2 OUT T1IN 18 T2 T2IN 1 OUT 4 R1 R1 3 19 R2IN R2OUT 20 OUT IN 11 8 C1+ C2+ 15 13 C1C2+ 10 V- 12 C216 17 VC214 GND GNDV+ 6 1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 9 9 MAX707 +5V U10 1 MR RESET 2 RESET V SW1 3 CC GND N.C. RESET 4 PFO PFI P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 RXD TXD -INT0 -INT1 T0 T1 -WR -RD RST C1 27pF18 8 7 6 5 AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 ALE -EA A15 A14 A13 A12 A11 A10 A9 A8 39 38 37 36 35 34 33 32 30 31 28 27 26 25 24 23 22 21 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 11 2 1 Q1 D1 3 4 74HCT 5 573 6 U4 7 D 8 9 D8 Q8 15 14 13 12 11 10 9 8 XTAL2 29 XTAL1 -PSEN XX1 11.059MHz C2 1 U6 HCT08 27pF 3 2 +5V 4 U6 HCT08 6 +5V 12 5 19 0 0 18 1 1 17 2 2 16 3 3 15 4 4 14 5 5 13 6 6 12 7 7 8 9 10 11 12 13 10 9 8 7 6 5 4 3 25 24 21 23 2 26 22 20 A0 O0 A1 O1 A2 O2 A3 O3 A4 O4 A5 O5 A6 O6 A7 O7 A8 27C64 A9 U3 A10 A11 VPP A12 N.C./A13 PCM C E 11 12 13 15 16 17 18 19 +5V 1 27 19 14 2 A0 0 3 A1 U5 1 15 HCT139 2 1 EN 3 4 5 6 7 9 U6 HCT08 8 10 11 13 U6 HCT08 Figure 6. 80C32 Module Schematic 16 ______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit +5V RS1 U8 62256 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 10 9 8 7 6 5 4 3 25 24 21 23 2 26 1 20 22 27 A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 -CS -OE -WR I/O1 I/O2 I/O3 I/O4 I/O5 I/O6 I/O7 I/O8 11 12 13 15 16 17 18 19 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 1 19 2 DIR EN B1 3 A1 4 74HCT 5 /245 6 U7 7 H 8 9 A8 B8 10k 18 17 16 15 14 13 12 11 12 0 11 1 LS139 10 2 U5 15 9 EN 3 13 ADDR0-4 15-18 DB00-DB07 19-26 14 A0 13 A1 12 3 Evaluates: MAX186 0 1 2 -CS0 - -CS3 11-14 -RD 9 -WR 10 RESERVED 35-40 +5V POWER LED R1 620Ω 70M05 U9 C4-C12 0.1µF + C3 47µF + C13 47µF VOUT VIN +5V 7-8 V++ 5-6 SW2 POWER SWITCH VIN POWER CONNECTOR C14 47µF GND GND 1-4 Figure 6. 80C32 Module Schematic (continued) ______________________________________________________________________________________ 17 Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit Figure 7. 80C32 Module Component- Side Layout (x2) 18 ______________________________________________________________________________________ MAX186 Evaluation System/Evaluation Kit Evaluates: MAX186 Figure 8. 80C32 Module Solder-Side Layout (x2) ______________________________________________________________________________________ 19 Evaluates: MAX186 MAX186 Evaluation System/Evaluation Kit Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 20 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.