a Evaluation Board for Microprocessor System Temperature Monitor EVAL-ADM1022 FEATURES External Temperature Measurement with Remote Diode (Two Channels) On-Chip Temperature Sensor Interrupt and Overtemperature Outputs Fault Tolerant Fan Control Brownout Detection LDCM Support I2C Compatible System Management Bus (SMBus) Standby Mode to Minimize Power Consumption Limit Comparison of all Monitored Values EVALUATION SYSTEM PACKAGE CONTENTS APPLICATIONS Network Servers and Personal Computers Microprocessor-Based Office Equipment Test Equipment and Measuring Instruments EVALUATION BOARD HARDWARE INTRODUCTION The evaluation system package contains the following items: * This application note * ADM1022 evaluation board * DIMM interface card * Centronics cable * DIMM interface ribbon cable * Evaluation software on floppy disks The ADM1022 evaluation board contains the following main components, which can be identified from the block diagram, printed circuit board silk screen and schematic diagram of figures 1, 2 and 3 overleaf. The ADM1022 Evaluation Board allows the ADM1022 microprocessor system hardware monitor IC to be easily evaluated using a personal computer. Using both the evaluation board and its accompanying software, the ADM1022 can be interfaced to any personal computer running WindowsTM 95 or WindowsTM 98, via the computer’s parallel printer port, or via the computer’s SMBus using the DIMM interface card provided. * ADM1022 I.C. The evaluation board allows all the input and output functions of the ADM1022 to be exercised without the need for external components. The software allows control and monitoring of the ADM1022’s internal registers. * Connectors for parallel and SMBus interface THE ADM1022 REQUIREMENTS The following gives a brief description of the ADM1022. More detailed device information can be found in the datasheet for the device. The ADM1022 is a hardware temperature monitor for personal computers and other microprocessor systems which features a three-channel digital thermometer and over-temperature alarm. It can also control the speed of a cooling fan. * PC running Windows 95 or Windows 98 * NPN and PNP sensor transistors * LED indicators for power, resets, interrupt, over-temperature, fan off request, and fan full-on * Switches for selecting voltage monitoring source, temperature sensors, and for setting device’s SMBus address * Interface buffers * Test connector * 3.3V supply regulation circuit * 15Vdc 300mA regulated power supply The device can measure local temperature using an onchip diode connected transistor, or can use low cost, small signal transistors such as the 2N3904 or 2N3906 to measure the temperatures of 2 external microprocessors. The measurement technique implemented, cancels the absolute value of the transistor’s base emitter voltage, so that no calibration is required. REV. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 Analog Devices, Inc., 1998 EVAL-ADM1022 V DD V DD V DD D3 FAN_OFF SW2 D6 RED INTERRUPT ADD 10-WAY CONNECTOR FOR SMBUS (J4)* FAN_OFF MR PNP SENSOR DIMM INTERFACE CARD INT SDATA PARALLEL PORT ADM1022 BUFFERS D2+ NPN SENSOR D2SCLK D1+ 36-WAY CENTRONICS CONNECTOR (J2)* D2+ EXTERNAL SENSOR D1D2D1+ PC FAN_SPD V DD RST1 V DD USE EITHER J2 OR J4 BUT NOT BOTH RST2 D1SCLK SDA RESET GND VMON TEST CONNECTOR J1 FAN D1 D2 AUX_RST V DD D4 GREEN POWER V DD Figure 1. ADM1022 Evaluation Board Block Diagram Figure 2. ADM1022 Evaluation Board SilkScreen –2– REV. B ADM1022.sch-1 - Tue Dec 08 11:59:10 1998 REV. B –3– EVAL-ADM1022 EVAL-ADM1022 CONNECTORS, SWITCHES AND INDICATORS TABLE 2. REMOTE SENSOR SELECT; SW4, SW3 The function of the various connectors, switches and indicators on the evaluation board is explained below. SW4 Position SW3 Position 1 2 TEST CONNECTOR J4 Test connector J4 allows the serial data and clock lines of the ADM1022 and the THERM line to be monitored. The connector also allows access to the VMON and GPI lines. Alternative external diode sensors may be connected between the D1 and D2 pairs of inputs. CENTRONICS INTERFACE CONNECTOR J2 If the personal computer being used with the evaluation board does not have a System Management Bus on the motherboard, connection between the evaluation board should be made via a parallel printer port, using the cable provided. The connections to J2 are as follows: TABLE 1. J2 CONNECTIONS J2 Pin ADM1022 Function Parallel Port Function 2 Serial Clock (SCLK) DB0 3 Serial Data In (SDA) DB1 8 Manual Reset (MR) DB6 10 Interrupt (INT) ACK 13 Serial Data Out (SDA) SLCT Gnd Gnd 19-30 Sensor Selected OFF OFF C D1/D2(connector J4) ON - A 2N3906 (D2) - ON - 2N3904 (D1) ON ON A D1 and D2 selected SERIAL BUS ADDRESS SELECT (SW2) SW2 is used to set the two LSB’s of the ADM1022’s serial bus address, A1 and A0. The ADD pin is tri-state and can be grounded, left unconnected or tied to VCC. This means a total of three addresses are possible. It should be noted that the ADD pin is only read at power-up. If SW2 is changed while the ADM1022 is on, the change of address will not be effective until the device has been powered off, and on again. As the serial bus address is 7 bits, when storing it as an 8bit word it must be left or right justified, with either the MSB or the LSB of the 8-bit word as zero. The ADM1022 evaluation software stores the 7-bit serial bus address as left-justified and makes the LSB zero. Table 3 shows the three possible addresses for the ADM1022. TABLE 3. ADM1022 DEVICE ADDRESSES SW2 Position A1 A0 Device Address A (Gnd) 1 0 5C (Hex) B (NC) 0 0 58 (Hex) C (Vcc) 0 1 5A (Hex) SMBUS INTERFACE CONNECTOR J3 The SMBus interface connector J3 allows the evaluation board to be connected directly to the SMBus of a personal computer, using the DIMM interface card provided. To make this connection, it may be necessary to remove one of the DIMM memory modules on the PC motherboard, if all DIMM sockets are occupied. This will affect the BIOS setup and Windows 95, and should only be attempted by a competent user. VMON SELECT SWITCH, SW1 This switch allows the VMON pin to monitor either the onboard 3.3V supply, an external 3.3V supply through connector J4, or a larger external supply voltage through J4, applied across voltage divider network R4, R5. Table 4 shows the relevant switch positions. TABLE 4. VMON SELECT SWITCH, SW1 SW1 Position REMOTE SENSOR SELECT SWITCHES SW4, SW3 Two remote sensors are provided on the evaluation board; a 2N3904 and a 2N3906 transistor. Alternative remote sensors may be connected between the D1 and D2 terminals on the test connector J4. –4– Voltage Source (Vmon) A External 5V on J4 B External 3.3V on J4 C On-board 3.3V REV. B EVAL-ADM1022 D2/THERM THERM SELECT SWITCH, SW3 INSTALLING THE SOFTWARE This switch selects either the on-board 2N3906 temperature sensing transistor, or an off-board transistor connected to the D2 inputs of test connector J4. To install the software, insert the first disk of the program software supplied into drive A, click on the Start icon, click on Run, and then type A:setup.exe as the file name. If the 3.5-inch floppy disk drive is not drive “A”, type “X” instead of “A”, where “X” is the drive letter of the 3.5-inch floppy disk drive. If a second thermal diode is unwanted, the THERM function on the ADM1022 may be used. If THERM is selected, LED D7 will indicate any over-temperature measurements. TABLE 5. D2/THERM THERM SWITCH, SW3 SW3 Position Selected Function A Remote D2 on J4 B Over-temperature and fan full-on status on LED D7 C USING THE SOFTWARE When using the software, first ensure that the evaluation board is connected to the Parallel printer port, or to the PC’s SMBus using the DIMM interface card. To start the software, select Start- Programs- ADM1022 Evaluation Software. When the program is started, the Software Initialisation Wizard screen will appear. On-board 2N3906 RESET SWITCH, PB2 When this pushbutton switch is pressed, it will assert RST2 low. RST2 will remain low for tRP after PB2 is released. This can be used to reset some external circuitry. FAN FULL-ON SWITCH, PB1 When this pushbutton switch is pressed, THERM is pulled low. This causes the FAN_SPD output to go fullscale (2.5V), and the fan goes to full speed. The FAN FULL-ON LED, D7 also lights up. TABLE 6. INDICATOR LED’s LED WHEN LIT D1 When RST2 asserts on power-up or PB2 is pressed. D2 When RST1 asserts on power-up. D3 When FAN_OFF output is asserted. D4 When board is powered. D6 When an interrupt condition occurs. D7 When an over-temperature condition occurs (THERM asserted), or when the fan is set to full speed by pressing PB1. THE SOFTWARE The software allows the ADM1022’s functions to be controlled from the PC via an easy to use interface, operating under the Windows environment. The contents of the device’s internal registers can easily be read or altered through a user-friendly graphical interface, while the Visual Display window allows temperature readings to be graphed. REV. B –5– EVAL-ADM1022 Click on “Next” to go on to the next screen, which allows the user to select between connection of the evaluation board via the printer port or to the SMBus using the DIMM interface card. The software will search for the ADM1022, and when it is found, the following screen will appear. The device address found will depend on the setting of Address Select switch, SW2. Once the communications medium has been selected, click on “Next” to go to the next screen. When you are ready for the software to begin searching for the evaluation board on either the parallel port or the SMBus, click “Next”. If “Yes” is selected, then the following message appears. If “No” is chosen, then the software will search for another ADM1022 device at a different address. This feature is useful if multiple ADM1022’s exist on the same SMBus and you need access to one of the devices at a different address. –6– REV. B EVAL-ADM1022 In this case, check the connections to the evaluation board, click on “< Back” and try again. If this does not work, then try re-booting the PC and re-running the software. When the software has successfully found the ADM1022, click on “Finish”. An index-card type display with three tabs will appear. The main tab is the splash screen. It shows the software version and clicking on the “About” button, pops-up the About dialog box showing more information on the software. On-line help may be accessed at any time during the software’s use by pressing F1 on the keyboard. It is also possible to quit the program by clicking on the close button If the ADM1022 is not found on the printer port, the following message will appear:- If the ADM1022 is not found on the SMBus, the following message will appear:- REV. B –7– EVAL-ADM1022 Figure 3. Main Program Tab READ/WRITE This tab displays information about the ADM1022’s internal registers. It allows their contents to be read and/or altered. Each register has a label associated with it printed on the tab. Moving the mouse pointer over the label changes the register label colour to light green. When the register label is clicked, it becomes a highlighted yellow. Now this register will become the default on-screen register and the register label will turn dark green to indicate this. The contents of the selected register will be displayed in the register contents box, along with the name of each individual register bit. The register contents are also displayed in hexadecimal and decimal format. Clicking on a register label will cause its contents to be read once if continuous reading is off. If continuous reading is on, the register contents will be displayed continuously; allowing any register bit changes to be viewed immediately. When a register label is clicked, it performs a single read of that register from the ADM1022. Therefore, continuous reading will be off:- If however, the user wishes to continuously monitor the selected register, then this can be done by toggling the continuous reading button to its on-state. When a register label has been clicked, the Read/Write portion of the form reflects each individual bit of the selected register. Thus, any bit of the register may be modified or monitored in this box. –8– REV. B EVAL-ADM1022 Alternatively, the entire contents of a register may be changed by typing a Hex or Decimal value in the “Write” text box. When the contents of the text box is altered, the button alongside will change from green to red, signifying a newly entered value. Clicking on the red button will write the updated value to the selected register. VISUAL DISPLAY The Visual Display tab allows all three temperature measurement channels to be monitored and graphed. EASY SETUP At the bottom of the Visual Display Tab is the “Easy Setup” button:- This feature is useful where a register contains a numeric value, such as a temperature limit. Another useful portion of the form provides info about the selected register; the address of the register, and the previous values read and written to/from the register. If the ADM1022 has been configured for only one remote thermal diode, then pressing “Easy Setup” will graph the Internal Temperature and the Remote Diode temperature. If the ADM1022 has been configured for both remote thermal diode channels, then pressing the “Easy Setup” button will graph the Internal Temperature and the two Remote Diode temperature channels. Figure 4. Read/Write Program Tab REV. B –9– EVAL-ADM1022 BARGRAPH On the left-most position of the Visual Display tab is the bargraph control/indicator. This 3D-type indicator gives a visual indication of the selected temperature channel. The bargraph also has 2 moveable controls; these control the upper and lower interrupt limits which may be set for each temperature channel. Once the temperature moves outside these limits, an interrupt will be generated if the interrupt source is unmasked in the Interrupt Mask Register (please refer to the ADM1022 datasheet for more detailed interrupt information). As shown above, when the temperature goes beyond a programmed temperature limit (86°C in this case), an interrupt is generated and the LED lights up for that channel. External 1 is the channel being displayed, since the label is green. The absolute temperature on that channel is 112°C, as shown at the base of the temperature bargraph. FAN SPEED CONTROL Each temperature channel’s limits may be adjusted independently of the next channel, by selecting the channel from the bargraph panel on the Visual Display tab. The channel may be selected by clicking on it, and will turn green to indicate its selection. The ADM1022 can control the speed of a fan connected to it. This tab contains a slider control to manually adjust the default fan speed. The temperature value is displayed below the bargraph, allowing absolute readings to be monitored. The bargraph gives a useful indication of whether temperature is rising or falling, and the rate at which it is doing so. If the temperature goes outside the programmed limits, an error is generated for that channel, and the bargraph panel will give a visual indication of this. –10– REV. B EVAL-ADM1022 GRAPHING On the right-most of the Visual Display tab is a line graph. Once the “Easy Setup” button is clicked, graphing begins. Each temperature channel is plotted against time. The graph contains a colour legend to associate each coloured line with each temperature channel. While the display is graphing, the user can click on the Read/Write tab, and make any adjustments, without having to stop the graphing. This feature can be useful for enabling or disabling interrupts, or other functions, whilst still measuring temperature. While the graph is displayed on the screen, it is possible to zoom in or out by moving the arrows on the temperature and time axes. Moving the lower arrow up the temperature axis, increases the minimum temperature shown on the graph, while moving the upper arrow down decreases the maximum temperature displayed. This effectively allows zooming in on a narrower temperature range. Similarly, moving the left arrow to the right on the time axis and/or the right arrow to the left, displays a narrower band of time on this axis. The graph can be cleared at any time by pressing the “Easy Setup” button again. Note that doing so will cause all the registers to be re-initialised to their default values. Figure 5. Visual Display tab REV. B –11– EVAL-ADM1022 Figure 6. Normal Graph Fig 7. Zoomed In Graph –12– REV. B EVAL-ADM1022 APPENDIX A. ADM1022 REGISTERS More detailed information on each of the registers may be found in the ADM1022 datasheet. TABLE7. LIST OF ADM1022 REGISTERS Register Name Address A7 - A0 in hex Comments 0x13 – 0x3A See Table 8 Company ID 0x3E This location will contain the company identification number. This register is read only. Revision 0x3F This location will contain the revision number of the part in the lower four bits of the register [3:0]. The upper four bits reflect the ADM1022 Version Number [7:4]. The first version is 1100. The next version of ADM1022 would be 1101, etc. For instance, if the stepping were A0 and this part is a ADM1022, then this register would read 1100 0000. This register is read only. Configuration Register 0x40 Power on value = 0010 0101 Interrupt Status Register 0x41 Power on value = 0000 0000 Interrupt Mask Register 0x43 Power on value = 0000 0000 0x4C Power on value = 0000 0000 Value Registers Interrupt Status Register Mirror TABLE 8. REGISTERS 0X13- 0X3A VALUE REGISTERS Address Read/Write Description 0x13 Read/Write Programmable Local Temp Sensor Automatic Trip Point - default 70 degrees C. This register can only be written to if the write once bit in the configuration register (0x40, bit 3) has not been set. 0x14 Read/Write Programmable Remote Thermal Diode Automatic Trip Point - default 100 degrees C. This register can only be written to if the write once bit in the configuration register (0x40, bit 3) has not been set. 0x15 Read/Write Test register for manufacturer’s use only. Do not write to this register 0x17 Read Only Default Local Temp Sensor Automatic Trip Point - default 70 degrees C Cannot be changed. Disabled when bit 3 of Config. register is set 0x18 Read Only Default Remote Thermal Diode Automatic Trip Point - default 100 degrees C Cannot be changed. Disabled when bit 3 of Config register is set 0x19 Read/Write Analog Output, FAN_SPD (defaults to 0x00h) 0x20 Read Only External Temperature Value Diode 2 0x26 Read Only External Temperature Value Diode 1 0x27 Read Only Internal Temperature 0x2B Read/Write External Temperature Diode 2 High Limit 0x2C Read/Write External Temperature Diode 2 Low Limit 0x37 Read/Write External Temperature Diode 1 High Limit 0x38 Read/Write External Temperature Diode 1 Low Limit 0x39 Read/Write Internal Temperature High Limit 0x3A Read/Write Internal Temperature Low Limit REV. B –13– EVAL-ADM1022 APPENDIX B. COMPONENT LIST Capacitors C1,C2,C3 10µF tantalum C4,C5,C6 0.1µF Resistors R1 47k R2,R4,R5,R15 10k R3,R6,R7,R9,R14,R16 680R R8 80R R10,R11,R12,R13 2k2 Semiconductors Q1,Q3 2N3904 Q2 2N3906 D1,D2,D4 Green LED D3,D6,D7 Red LED D5 1N4001 U1 ADM1022 U2 AD820 U4 74HC05 U6 78L033 Connectors J1 Power socket J2 36-way Centronics J3 10-way R.A. IDC socket J4 2mm 8-way test socket J5,J6 Terminal post Switches SW1,SW2,SW3 3-way slide switch SW4 DIL switch PB1,PB2 pushbutton switch Miscellaneous U3 12V dc fan –14– REV. B