STFPC311 Front panel controller/driver with standby power management Features ■ IC front panel controller/driver ■ Timing power standby management controller ■ IC power supply from 3.3V (VDD) to –30V (VSS) ■ Integrated VFD driver and controller ■ Infrared (IR) Remote Control (RC) Decoder (Philips or NEC format) ■ Drives many display modes (12 segments/16 digits to 20 segments/8 digits) ■ High voltage outputs (VDD - 33.3V max) ■ No external resistors necessary for driver outputs (P-channel open- drain with pull-down resistor outputs) ■ Key scanning (up to 12mm x 2mm matrix) ■ Led ports (4 channels, 20mA, max) ■ Serial interface (STB, CLK, DIN, and DOUT) communication protocol ■ Dimming circuit (adjustable up to 8 steps) ■ Supports auto-increment of display digit, which lightens the load on the MCU ■ Programmable 8 hot keys for the IR remote control command ■ Programmable 8 hot keys for key scan command ■ Low power consumption in standby mode ■ 2 general purpose input ports (SW1, SW2) ■ Available in PQFP-52 package Order Codes May 2006 PQFP-52 Description The STFPC311 is a complete, low-cost, integrated solution for controlling and driving a front panel Vacuum Fluorescent Display (VFD). It is ideal for decreasing power consumption in standby mode by reducing the application standby current to a minimum. It also contains a built-in remote control decoder module. While in the standby mode of operation, a valid key press or signal from infrared decoder will start a proper power-up see Figure 6 on page 12. The STFPC311 integrates a VFD controller with a driver that is run on a 1/8 to 1/16-duty factor. It consists of 12 segments output lines, 8 grid output lines, 8 shared segments/grid output drive lines, a display memory, a control circuit, and a key scan circuit. Serial data is input to the STFPC311 through the SPI Interface of a microcontroller (STB, DIN, DOUT, and CLK). Additionally, this IC can support 2 general purpose input switches (SW1 and SW2). Features ■ DVD players ■ VCD players ■ AV equipment like Home Stereo ■ POS Systems Part number Temperature range Package STFPC311 -40 to 85°C PQFP-52 Rev 1 1/39 www.st.com 39 STFPC311 Contents 1 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1 2 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 3 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 Normal mode of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2 Receive operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.3 Transmit operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.4 Standby or power-down mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.5 IR Decoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.6 Watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.7 3.6.1 Watchdog timer operation during power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.6.2 Watchdog timer operation during power-down . . . . . . . . . . . . . . . . . . . . . . . 10 3.6.3 Watchdog timer operation during standby . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Flow charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4 Display RAM address and display mode . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6 7 2/39 5.1 LED Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5.2 SW Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.1 Configuration mode setting command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.2 Data setting command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.3 Address setting command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.4 Display control and hotkey setting command . . . . . . . . . . . . . . . . . . . . . . . . 20 Programmable hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7.1 IR Remote control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7.2 Front panel keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 STFPC311 8 9 10 Default status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 8.1 Power-up default status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 8.2 STANDBY status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Remote control protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9.1 RC-5 remote control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9.2 SPI interface IR data transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 9.3 NEC remote control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 10.1 Power consumption estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 11 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 12 Timing characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 13 Serial communication format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 14 Typical application diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 15 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 16 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3/39 STFPC311 1 Functional description 1 Functional description The STFPC311 receives serial data from the microcontroller through the SPI interface, latches the data, and then masks the inputs from the MCU. This data consists of commands followed by data. There are 4 types of commands: ● configuration, ● data, ● address, and ● display. The STFPC311 integrates the supply standby power management functionality, remote control decoder, and a 28-bit VFD driver. Microcontrollers usually run the first two tasks. This device reduces the stand-by power consumption of the whole Front Panel application as well as the hardware by integrating the infrared (IR) remote control decoder. A dedicated supply voltage powers the STFPC311 directly from the main supply board. When power is plugged in, control of the power supply management is done using the following pins: 1.1 1. STBY, 2. IR_DATA_IN, and 3. READY. Block diagram Figure 1. Block diagram Remote Control Decoder & Stand By Function IR_DATA_IN READY/STBY_n STBY MUTE SPI Serial I/F Display Memory (20 x 16) VDD OSC KEY1 KEY2 Key Data Memory (2 x 12) 16-bit Shift Register 16 2 2 4/39 SEG13/GRID16 SEG12/KS2 8 SEG20/GRID9 8 2-bit Latch SW2 SEG1/KS1 8 Data Selector Timing Generator Key Scan and Dimming Circuit ROSC SW1 20-bit Output Latch 12 4-bit Latch LED1 LED2 LED3 LED4 VDD GND VSS (+3.3V) (0V) (-30V) 8 Grid Drivers CLK STB 20 Segment Drivers Command Decoder DIN DOUT Multiplexed Drivers Watchdog Timer GRID8 GRID1 STFPC311 2 Figure 2. 2 Pin connection Pin connection Connection diagram (top view PQFP-52) STFPC311 Note: For a description of the behavior of each pin, refer to the Table 1: Pin description on page 6. 5/39 STFPC311 2 Pin connection 2.1 Pin description Table 1. Pin description Pin Nº Symbol Type Name and function 1 OSC I This is the oscillator input pin. Connect this pin to an external resistor. 2, 3 SW1, SW2 I General purpose switch input ports. 4 MUTE O High level indicates mute status for audio. Low level indicates normal working.Note 1 there is a typo. Pin5 and name is STBY. Standby output to put the MCU in low power mode. It is a command to the main power board. High level indicates stand-by status. Low level indicates normal working. Note 1 5S TBY O 7 GND POWER 8, 9 KEY1, KEY2 I Input data to these pins from external keyboard are latched at end of the display cycle (maximum keyboard size is 12 x 2). 10 READY I High level on this pin means that main board chip has been working normally.Note 1 This pin should never float. It is recommended have a pull-down resistor on this input. 1 IR_DATA_IN I Remote control input. Feeds the IR data from photodiode to this pin. 14 to 25 SEG1/KS1 to SEG12/KS12 O Segment output pins (dual function as key source). 12, 26 VSS POWER 27 to 34 SEG13/GRID16 to SEG20/GRID9 O These pins are selectable for segment or grid driving. 35 to 37 GRID8 to GRID6 O Grid output pins. 6, 13,38 VDD POWER 39 NC O Not used. Left unconnected. 40 to 44 GRID5 to GRID1 O Grid output pins. Connect this pin to system GND. VFD outputs high voltage pull-down level. VDD--33.3V max. 3.3V ± 0.3V Core main supply voltage. 45 STB I Initializes the serial interface at the rising or falling edge to make the STFPC31 wait for reception of command. The data input after the falling edge of STB is processed as a command. While the command data is processed, current processing is stopped, and the serial interface is initialized. While STB is high, CLK is ignored and any instruction from the MCU is neglected. 46 CLK I Reads serial data at the rising edge, and outputs data at the falling edge. 47 DIN I Inputs serial data at the rising edge of the shift clock, starting from the lower bit. 48 DOUT O Outputs serial data at the faling edge of the shift clock, starting from the lower bit. This is the N-channel opendrain output pin. 49-52 LED1, LED2, LED3, LED4 O CMOS outputs (20mA, max). Note: 1 For a detailed behavioral description of these pins, refer to the “STFPC311 Timing Power Stand-by Sequencer Flow-Chart”. See Table 6 on page 12 6/39 STFPC311 3 3 Initialization Initialization After the power is plugged in, the device will supply power to all of the components (including the host processor) by setting STBY to logic low in order to allow the host processor to program the STFPC311. Once the STBY is set to low, the watchdog timer starts to count up to 10s (10s is the default value of the watchdog timer upon power-up). When the READY is asserted within this time, it indicates that the system has booted up well. If the READY pin is not asserted (logic high) within this time (10s), the STFPC311 will put the system into standby mode again by setting STBY to logic high. If READY is detected as logic high, the watchdog timer will be turned OFF. The main processor should program the remote control hot key and initialize the other parameters of the STFPC311 in preparation for normal operation before the system goes into standby mode. After all of the STFPC311 configuration is finished, the host processor may set the READY to low so that the STFPC311 enters standby mode. The STFPC311 then sets the MUTE pin to logic high to mute the audio output as well as the STBY pin to logic high. As a consequence of this action, the main supply voltage is turned off. 3.1 Normal mode of operation After the power is plugged in, the device will supply power to all of the components (including the host processor) by setting STBY to logic low in order to allow the host processor to program the STFPC311. Once the STBY is set to low, the watchdog timer starts to count up to 10s (10s is the default value of the watchdog timer upon power-up). When the READY is asserted within this time, it indicates that the system has booted up well. If the READY pin is not asserted (logic high) within this time (10s), the STFPC311 will put the system into standby mode again by setting STBY to logic high. If READY is detected as logic high, the watchdog timer will be turned OFF. The main processor should program the remote control hot key and initialize the other parameters of the STFPC311 in preparation for normal operation before the system goes into standby mode. After all of the STFPC311 configuration is finished, the host processor may set the READY to low so that the STFPC311 enters standby mode. The STFPC311 then sets the MUTE pin to logic high to mute the audio output as well as the STBY pin to logic high. As a consequence of this action, the main supply voltage is turned off. 3.2 Receive operation In receive condition, the STFPC311 waits for a valid command from the MCU. The receive circuit of STFPC311 receives 8 bit serial data, latches the data and then masks the inputs from the MCU. Refer to Figure 28 on page 32 for receive timing. 3.3 Transmit operation In transmit condition, the STFPC311 sends the 8-bit serial data (LSB transmitted first) whenever a key is pressed or IR data is received. STFPC311 transmits data on the falling edge of CLK. Refer to Figure 29 on page 32 for transmit timing. 7/39 3 Initialization 3.4 STFPC311 Standby or power-down mode Once the STFPC311 detects the status change of the READY to a logic low or after the preset waiting time (1s to 15s) has elapsed, the STFPC311 sets the STBY pin to a logic high to turn off the power. The MUTE signal is set to high before the power is turned off. The STFPC311 always senses the level on the READY pin during normal operation. 3.5 IR Decoding Encoded IR data from photodiode is supplied to the IR_DATA_IN input pin. The data is decoded by the internal remote control decoder module of STFPC311. In standby mode, the remote control decoder recognizes a set of predefined commands (such as STANDBY, PLAY, and OPEN/CLOSE), and takes appropriate action to manage the power supply. These predefined commands are known as "hot keys" and are programmable. The decoded IR commands are passed on to the main processor through the SPI interface by sending 3 bytes of data on the DOUT pin. 3.6 Watchdog timer The watchdog timer is used to detect an out-of-control microprocessor. The watch dog timer is implemented in the STFPC311 to detect the abnormal processor behavior or processor-hung condition. The default state of the watchdog timer is 10s when the device powers-up. It is initialized by writing to the watchdog register and can be programmed to up to 15s (4-bit watchdog timer, present in the configuration mode setting command). If the processor does not reset the timer within the specified period, the STFPC311 will put the entire system into standby mode to reset the appliance that has stopped abnormally. The action to take when the watchdog timer has reached its count is to set the Watchdog Action register. The watchdog timer can be reset by the host processor by sending a command to reset the watchdog timer. The time-out period then starts over again. If the processor needs to be reset as a result of a hung condition (signalled using the STBY output of the STFPC311), the watchdog timer uses the amount of the time-out programmed into the Watchdog Register by the user to generate an interrupt. Note: The accuracy of the timer is within ±10% the selected resolution. This depends on the value of the external bias resistor, as it determines the internal clock frequency. The watchdog function is automatically set to 10s upon power-up and the Watchdog Interrupt is cleared. This boot-up watchdog timer is used to make sure that if the host processor hangs during the first boot-up, the STFPC311 will put the system to standby mode. During the first boot-up, the watchdog timer is disabled after the first READY signal is received. 8/39 STFPC311 3.6.1 Figure 3. Note: 3 Initialization Watchdog timer operation during power-up Power-up condition Watchdog timer is turned off by default upon READY assertion. If Watchdog is to be kept on during READY high condition, the WDG registers must be set accordingly by proper commands through SPI bus. In this power-up condition, the watchdog timer is triggered by internal POR pulse. During power-up, the watchdog timer value is 10s. 9/39 3 Initialization 3.6.2 Figure 4. Note: STFPC311 Watchdog timer operation during power-down Power-down condition The watchdog timer can be kept on during normal conditions when READY is high (depending on the user’s settings). In this condition, the watchdog timer can be disabled or enabled. If the watchdog timer is enabled, the timer needs to be cleared before the programmed count of the timer is reached. If the programmed count is reached, the STBY will be asserted. Caution: It is advisable not to enable the watchdog timer during normal operation. 10/39 STFPC311 3.6.3 Figure 5. 3 Initialization Watchdog timer operation during standby ● When a hot-key signal is detected either from the front panel or remote control during standby, the STBY de-asserts. ● The de-assertion of the STBY triggers the watchdog timer. ● The timer value is the programmed value that is set by the user (1s-15s). If the user did not change the value before entering standby, then it remains 10s. ● Also note: that The watchdog timer is off when the STFPC311 is in the standby mode to save power. Standby condition 3 a ) S ta n d b y C o n d itio n (N o rm a l b e h a vio r ) H o t ke y co m m a n d fro m IR o r K e y p a d fo r w a ke u p W D G tim e r trig g e rs STBY READY R E A D Y a sse rts w ith in p ro g ra m m e d tim e r va lu e (1 s-1 5 s) MUTE 3b ) S ta n d b y C o n d itio n ( A b n o rm a l b e h a vio r, p ro c e s s o r is n o t re s p o n d in g) H o t ke y co m m a n d fro m IR o r K e y p a d fo r w a ke u p W D G tim e r trig g e rs S ig n a ls S T B Y a fte r W D G co u n t is o ve r STBY READY R E A D Y co n tin u e s to re m a in lo w MUTE The watchdog timer is triggered by a de-assertion of the STBY signal or by the internal Power-on Reset signal. It is not affected by the STB pin. 11/39 3 Initialization 3.7 Figure 6. Flow charts Timing power standby sequencer flow chart * Programmable from 1 to 15s. † FPK = Front Panel Keys 12/39 STFPC311 STFPC311 Figure 7. 3 Initialization IR RC command and front panel key operation flowchart. 13/39 3 Initialization Figure 8. Watchdog timer first power-up operation Figure 9. Watchdog timer operation 14/39 STFPC311 STFPC311 4 4 Display RAM address and display mode Display RAM address and display mode The display RAM stores the data transmitted from an external device to the STFPC311 through the serial interface and is assigned addresses, in units of 8-bits see :Table 2. Only the lower 4 bits of the addresses assigned to Seg17 through Seg20 are valid, the higher 4 bits are ignored. Note: The common grid/segment outputs are grid-based. The grid has to be enabled before any segments can be turned on. If data is written for a segment before enabling its grid, there is nothing on the display. Table 2. Seg1 Assigned addresses Seg4 Seg8 Seg12 Seg16 Seg20 00 HL 00 HU 01 HL 01 HU 02 HL DIG1 03 HL 03 HU 04 HL 04 HU 05 HL DIG2 06 HL 06 HU 07 HL 07 HU 08 HL DIG3 09 HL 09 HU 0A HL 0A HU 0B HL DIG4 0C HL 0C HU 0D HL 0D HU 0E HL DIG5 0F HL 0F HU 10 HL 10 HU 11 HL DIG6 12 HL 12 HU 13 HL 13 HU 14 HL DIG7 15 HL 15 HU 16 HL 16 HU 17 HL DIG8 18 HL 18 HU 19 HL 19 HU 1A HL DIG9 1B HL 1B HU 1C HL 1C HU 1D HL DIG10 1E HL 1E HU 1F HL 1F HU 20 HL DIG11 21 HL 21 HU 22 HL 22 HU 23 HL DIG12 24 HL 24 HU 25 HL 25 HU 26 HL DIG13 27 HL 27 HU 28 HL 28 HU 29 HL DIG14 2A HL 2A HU 2B HL 2B HU 2C HL DIG15 2D HL 2D HU 2E HL 2E HU 2F HL DIG16 b0 b3 b4 b7 XX HL XX HU Lower 4 bits Higher 4 bits 15/39 4 Display RAM address and display mode STFPC311 The data of each key is stored READ by a read command, starting from the least significant bit. see Figure 11.. When the most significant bit of data (Seg12b7) has been read, the least significant bit of the next data (Seg1b0) is read. Figure 10. Key matrix (12 x 2 configuration) and key-input data storage RAM Figure 11. Key storage and READ access 16/39 STFPC311 5 Data 5.1 LED Port 5 Data Data is written to the LED port by a WRITE command, starting from the least significant bit of the port see Figure 12. When a bit of this port is set to 0, the corresponding LED lights up; when the bit is set to a 1, the LED turns off. The data of Bits 5 through 8 are ignored. Upon first power-up, all of the LEDs are turned off. Figure 12. LED port data WRITE command order 5.2 SW Data The SW data are read by the appropriate READ command, starting from the least significant bit see Figure 13. Bits 3 through 8 of the SW data are 0. Figure 13. SW data READ Command order 17/39 STFPC311 6 Commands 6 Commands A command sets the display mode and status of the VFD driver. The first 1-byte input to the STFPC311 through the DIN pin after the STB pin goes low is regarded as a command. If STB is set to high while commands/data are transmitted, the serial communication is initialized and the commands/data being transmitted are invalid (however, the commands/data already transmitted remain valid). 6.1 Configuration mode setting command This command initializes the STFPC311 and performs any one of the following functions see Figure 14. a) Selects the number of segments and number of grids (1/8 to 1/16 duty, 12 segments to 20 segments). When this command is executed, the display is turned off. To resume display, the Display ON command must be executed. If the same mode is selected, nothing is performed. b) Selects the remote control protocol to use. c) Sets the watchdog timer. The watchdog timer is configurable from 1s to 15s or turned off completely. d) Sets the watchdog action to perform when the watchdog timer counts. Two actions are allowed: no action, and set STBY to (logic) high level. Figure 14. STFPC311 Configuration mode setting command order Table 3. Note: 18/39 STFPC311 Configuration mode bit 3 through bit 0 settings Based on Bit 5 through Bit 4 settings. STFPC311 6 Commands Upon power application, the following modes are selected: 6.2 ● Display Mode Setting: the 16-digit, 12-segment mode is selected (default: display off and key-scan on). ● Remote Control Protocol Setting: RC-5. ● Watchdog Timer Setting: Turned on with 10s. After the first command is processed by STFPC311, the watchdog timer is turned off until it is turned on by the host. ● Watchdog action: Issue Standby. Data setting command This command sets the data WRITE and READ modes see Figure 15. Figure 15. STFPC311 Data setting command order 19/39 6 Commands STFPC311 When the application is powered-up, the normal operation mode and address increment mode is set with the default display memory address set to 00H. In the auto-increment address mode, the address command is sent once, followed by the data bytes. Alternatively, the data command can be sent, followed by the data bytes. In this case, when new display data is to be written, the last value of the address will be used and then incremented. Upon reaching the last display memory address, the address jumps to 00H. For fixed address mode, the address command has to be sent, followed by the display data. When next byte of data is to be written, the address command has to be sent again before the new display data byte. For RC-5 data reception (after the photodiode), a binary 1 is represented by a high-to-low transition, and a binary 0 is represented by a low-to-high transition. For RC-6 (Mode 0) data reception, a binary 1 is represented by a low-to-high transition, and a binary 0 is represented by a high-to-low transition. Whenever Bit 5 is a ‘1’, the watchdog timer is reset. 6.3 Address setting command This command sets an address of the display memory. If address 30H or higher is set, the data is ignored until a correct address is set. Figure 16. STFPC311 Address Setting Command Order 6.4 Display control and hotkey setting command When the application is powered-up, the 1/16-pulse width is set and the display is turned OFF. See Figure 17 and Figure 4. All hot keys are disabled. Figure 17. STFPC311 Display control and hot key setting command order 20/39 STFPC311 Table 4. 6 Commands STFPC311 Address setting mode bit 3 through bit 0 settings 21/39 7 Programmable hotkeys 7 Programmable hotkeys 7.1 IR Remote control STFPC311 Eight (8) commands are user programmable for hot key functions. The address of the appliance (8-bit) is stored first into the internal RAM. Then, the command for the hot keys are programmed into the internal RAM. Each hot key memory address could accommodate one byte (8-bits). Usually one byte is reserved for one command. The RC data is only cleared when the READY is pulled low (system goes into STANDBY state). 7.2 Front panel keys Eight out of 24 keys are user programmable for hot key functions. Only keys from KS1 to KS4 can be programmed. Figure 18. Programmable hot keys (only KS1 to KS4, Box FPK1) 8 hot keys are to be placed in each address location as indicated by the hotkey setting command. Figure 19. HOTKEY setting command address locations (8 hot keys) For example, to store (Seg2/Key2) at the first location of the hot key RAM, the following commands are sent: ● 10110000 (command+address), and ● 00010000 (hot key mask). To store (Seg2/Key1), (Seg2/Key2), and (Seg4/Key1), the following commands are sent: ● 10110000 (command+address), and ● 00110010 (hot key mask). The same commands apply to FPK2 and FPK3 programming. Note: 22/39 Note: Reading the hot key values immediately upon STBY de-assertion is recommended. If they are not read within the watchdog preset timer value, the hot key data is cleared. STFPC311 7 Programmable hotkeys Figure 20. Recommended software flow Note: Resetting the front panel controller at ¾ of the set watchdog time is recommended. 23/39 STFPC311 8 Default status 8 Default status 8.1 Power-up default status Table 5. Default States S. N° 8.2 Functions Default Status 1 Display OFF 2 Key-scan ON 3 IR ON 4 Display mode 12 Seg/16Bit 5 Display address 00H 6 RC Protocol DC-5 7 LED OFF 8 Dimming 1/16 Duty factor 9 Hot Kets (IR and FP) Disabled 10 Watchdog timer 10s STANDBY status The display remains ON during STANDBY only if the -20V is present. If the -20V is absent, the display turns OFF. When the display wakes up from STANDBY and –20V is applied, the display turns ON with previous value. Switching off the display before entering the STANDBY state is recommended. When the same display configuration command is sent, the display remains ON. When the display configuration command is changed, the display is OFF. Only hot key detection can wake the system up from STANDBY condition. 24/39 STFPC311 9 Remote control protocols 9 Remote control protocols 9.1 RC-5 remote control RC-5 remote control protocol is based on Bi-phase (also known as Manchester) encoding as shown in Figure 21. Note: The encoding is set with reference to the IR_DATA_IN signal (after the photo diode). The MSB is transmitted first see Figure 22. ● The first two Start bits (S1 and S2) are synchronization bits. For normal operation, they are always set to '11' on the transmission side. After the photo diode, there is one inversion. The data at the IR_DATA_IN of the STFPC311 is shown in Figure 23 on page 25 ● The next bit is the Toggle bit. This bit is inverted each time a key on the remote control is pressed. ● Bits A1and A5 are the Address bits. The address bits indicate the intended application that the remote control protocol is used for. ● Bits C1..C6 are the Command bits. The command bits instruct the STFPC311 as to what action is to be taken. The data representing the RC-5 protocol is sent as a byte of data which consists of a Toggle bit and a ‘0’ bit followed by 6 bits of Command data. Figure 21. Bi-phase encoding Figure 22. RC-5 protocol frame Figure 23. RC-5 reception example 25/39 9 Remote control protocols 9.2 STFPC311 SPI interface IR data transmission The IR data is sent on the DOUT pin of the SPI interface when the micro controller issues a IR data read command. The data is sent in 3 bytes with LSB transmitted first as shown in the Figure below: The RC data consists of RC address, start bit, toggle bit and the RC command received. The extra bits are stuffed with 1’s to make it a 3-byte packet. These extra bits at the end of the packet should be ignored. Figure 24. RC-6 protocol frame The RC data consists of RC address, start bit, toggle bit and the RC command received. The extra bits are stuffed with 1’s to make it a 3-byte packet. These extra bits at the end of the packet should be ignored. 9.3 NEC remote control This remote control protocol uses pulse distance modulation. Each bit consists of a high level of fixed time "t", followed by a low level that varies in width. A space that is "t" represents a logic '0' and a space that is "3t" represents a logic '1'. t = 0.56ms. The LSB is transmitted first as shown in Figure 25 Figure 25. Pulse distance modulation. 26/39 STFPC311 9 Remote control protocols Figure 26. NEC protocol transmission waveforms 27/39 STFPC311 10 Maximum rating 10 Maximum rating Stressing the device above the rating listed in the “Absolute Maximum Ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 6. Absolute maximum rating ( TA = 25 °C, VSS = 0V ) Symbol Parameter Value Unit VDD Logic Supply Voltage -0.5 to +7.0 V VSS Driver Supply Voltage VDD + 0.5 to VDD – 40 V VI1 Logic Input Voltage -0.4 to VDD + 0.5 V VO2 VFP Driver Output Voltage VSS – 0.5 to VDD+ 0.5 V IO1 LED Driver Output Current +25 mA IO2 VFP Driver Output Current -40 (grid) -15 (segment) mA PD Power Dissipation 1200 (1) mA TA Operating Ambient Temperature -40 to +85 °C Storage Temperature -65 to +150 °C TSTG 1. Derate at -9.6 mW/°C at TA = 25 °C or higher Table 7. Symbol 28/39 Recommended operating conditions (TA = -20 to +70 °C, VSS = 0V) Parameter Min Typ Max Unit 3.0 3.3 3.6 V VDD Logic Supply Voltage VIH High-Level Input Voltage 0.7VDD VDD V VIL Low-Level Input Voltage 0 0.3 VDD V VSS Driver Supply Voltage 0 VDD-33.3 V STFPC311 10.1 10 Maximum rating Power consumption estimation The maximum power consumption is comprised of the Vacuum Florescent Display (VFD) driver dissipation, Load Resistance (RL), LED driver dissipation, and dynamic power consumption. PMAX = VFD + RL + LED + PDYN Where, ● PMAX = maximum power consumption, ● VFD = Vacuum Florescent Display driver dissipation, ● RL = load resistance, ● LED = LED driver dissipation, and ● PDYN = dynamic power consumption. If the segment current (ISEG) = 3mA, grid current (IGRID) = 15mA, and the LED current = 20mA, then: FIP = (#segments x 6) + [#grids/(#grids +1)] x 30mW, RL dissipation = (VDD – VSS)2 ÷ 50(segment + 1mW), LED driver dissipation = #LEDs x 20mW, and PDYN = VDD x 5mW. To finish this example: FIP driver dissipation = 16 x 6 + 12/13 x 30 = 124mW RL dissipation = 33.32/50 x 17 = 377mW LED driver dissipation = 2 x 20 = 40 PDYN = 3.3 x 5 = 16.5mW The maximum power consumption (Total) = 557.5mW Where, VSS = –30V, VDD = 3.3V, and the application is in 16-segment, 12-digit mode. 29/39 STFPC311 11 Electrical characteristics 11 Electrical characteristics Table 8. Electrical specifications (TA = -20 to +70°C, VDD = 3.3V, VSS = 0V, VSS = VDD - 33.3V) Symbol Parameter VOH1 High-Level Output Voltage LED1 – LED4, IOH1 = -1mA VOL1 Low-Level Output Voltage LED1 – LED4, IOH2 = 20mA VOL2 Low-Level Output Voltage DOUT, IOL2 = 4mA IOH21 High-Level Output Current VO = VDD – 2V, Seg1to Seg12 -3 mA IOH22 High-Level Output Current VO = VDD – 2 V, Grid1to Grid8, Se13g/Grid16to Seg20/Grid9 -15 mA IOLEAK Driver Leakage Current VO = VDD – 33.3 V, driver off RL I Test conditions Output Pull-Down Resistor Driver output Input Current VIL Low-Level Input Voltage VH Hysteresis Voltage CLK, DIN, STB Dynamic Current Consumption Under no load, display off Symbol tOSC tPLZ 100 1 V 0.4 V -10 µA 150 kΩ ±1 µA 0.7VDD V 0.3VDD Parameter 0.35 Oscillation Frequency Propagation Delay Time Test conditions V V 5 mA Min. Typ. Max. Unit 350 500 650 kHz CLK ≤DOUT 300 ns CL = 15pF, RL = 10KΩ 100 ns Seg1 to Seg12 2 µs Grid1 to Grid8, Seg13/Seg16 to Seg20/Grid9 0.5 µs 120 µs 1 MHz 15 pF R = 33KΩ ±5% tTZH1 Rise Time tTZH2 30/39 Unit Switching characteristics (TA = -20 to +70 °C, VDD = 3.3 V, VSS = -30 V) tPZL CL = 300pF tTHZ Fall Time CL = 300pF, Segn, Gridn fMAX Maximum Clock Frequency Duty = 50% CI Max. V VI= VDD or VSS High-Level Input Voltage Table 9. Typ. 0.9VDD 50 VIH IDD(DYN) Min. Input Capacitance STFPC311 12 12 Timing characteristics Timing characteristics Table 10. Timing characteristics ( VDD= 3.3V, TA= -20 to 70°C, unless otherwise noted. Typical values are at TA= 25°C ) Values Symbol Parameter Test conditions Unit Min. Typ. Max. PWCLK Clock Pulse Width 400 ns PWSTB Strobe Pulse Width 1 µs tSETUP Data Setup Time 100 ns tHOLD Data Hold Time 100 ns tCLK-STB tWAIT Clock-Strobe Time CLK STB 1 µs Wait Time (1) CLK CLK 1 µs 1. Refer to page on Serial Communication Format. The pulse width of the segment signal is derived from the oscillator frequency. The value can be modified by trimming ROSC. One cycle of key scanning consists of one frame and data of 12 x 2 matrices are stored in RAM. Note: The key scan is only at the end of the frame when the display is ON. When the display is OFF, the key scan takes place continuously. The grid is turned off during the key scan. Figure 27. Key scanning and display timing 31/39 13 Serial communication format 13 STFPC311 Serial communication format When data is read, a wait time (tWAIT) of 1µs is necessary within the rising edge of the eighth clock that has set the command, and the falling edge of the first clock that has read the data. This is required by the STFPC311 to process its internal commands/data (See Figure 28) Caution: Care must be taken to connect an external pull-up resistor to this pin (1kΩ to 10kΩ) because the DOUT pin is an N-channel, open drain output pin (see Figure 29). Figure 28. Recption (Command/data WRITE) Figure 29. Data transmission (data READ) 32/39 STFPC311 13 Serial communication format Figure 30. Switching characteristic waveforms fO SC O SC 50% P W STB STB P W CLK P W C LK tSETUP t H O LD t C L K -S T B CLK D IN tPZL tPLZ D OUT tTHZ S n/ G n tTZH 90% 10% 33/39 13 Serial communication format ● Command 1: sets display mode ● Command 2: sets data ● Command 3: sets address ● Data 1 to n: transfers display data (22 bytes max.) ● Command 4: controls display Figure 31. Updating display memory by incrementing address ● Command 1: sets data ● Command 2: sets address ● Data: display area Figure 32. Updating specific address 34/39 STFPC311 STFPC311 14 14 Typical application diagram Typical application diagram Figure 33. Typical application circuit R5 R6 12 x 2 KEY B O AR D D1 V DD KEY 1 KEY 2 D 12 SEG 1/K1 SEG 12/K12 V FD V DD + C1 8 G rids/Segments C2 S13/G 16 ~ S20/G 9 R OSC O SC < < < < < < < < < < < < Ef 1 ST FPC 311 8 G rids G1 ~ G8 STB 2 R1 C LK 3 4 5 6 D IN D OUT LED 1 IR _D AT A_IN LED 2 R EAD Y /STBY _n 7 M U TE STBY 9 LED 4 11 12 V DD 3.3V±0.3V V SS * -30V GND R4 V SS V SS 10 R3 LED 3 NC 8 R2 V DD C3 GND C4 + ● ROSC = 33kΩ ± 1% for oscillator resistor; ● R1 ~ R4 = 0.75 ~ 1.2kΩ; ● R5, R6 = 10kΩ for external keyboard pull-down resistor; ● C1 = 33µF-25V electrolytic; ● C2 = 0.01 ~ 0.1µF-25V ceramic; ● C3 = 0.01 ~ 0.1µF-63V ceramic; ● C4 = 33µF-63V electrolytic; ● D1 ~ D12 = 1N4148; ● Ef = filament voltage according with the VFD specs; ● VDD = 3.3V ±10%; * VSS = down to VDD – 33.3V. 35/39 15 Package mechanical data 15 STFPC311 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a Lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com. 36/39 STFPC311 Table 11. 15 Package mechanical data PQFP52 - 10x10x2 mm. plastic quad flatpack, package mechanical data Figure 34. Package dimensions 37/39 STFPC311 16 Revision history 16 Revision history Table 12. 38/39 Revision history Date Revision 09-May-2006 1 Change First release STFPC311 16 Revision history Please Read Carefully: Information in this document is provided solely in connection with ST products. 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