R EM MICROELECTRONIC - MARIN SA EM6521 MFP version of EM6621 Ultra Low Power Microcontroller with 4x20 LCD Driver Figure 1. Architecture Features • Low Power • • • • • • • • • • • • • • • • • - 11 µA active mode, LCD On - 1.8 µA standby mode, LCD Off - 0.1 µA sleep mode @ 3 V, 32 KHz, 25 ºC Large Voltage range, 2 to 5.5 V 2 clocks per instruction cycle 72 basic instructions EEPROM 4096 x 16 bits RAM 128 x 4 bits Max. 12 inputs ; port A, port B, port SP Max. 8 outputs ; port B, port SP Voltage Level Detector, 8 levels software selectable from 1.2 V up to 4.0 V Melody, 7 tones + silence inclusive 4-bit timer Universal 10-bit counter, PWM, event counter Prescaler down to 1 second ( crystal = 32 KHz ) 1/1000 sec 12 bit binary coded decimal counter with hard or software start/stop function LCD 20 Segments, 3 or 4 times multiplexed 3 wire serial port , 8 bit, master and slave mode 5 external interrupts (port A, serial interface) 8 internal interrupts (3x prescaler, BCD counter 2x10-bit counter, melody timer, serial interface) timer watchdog and oscillation supervisor Figure 2. Pin Configuration, TQFP52 10 * 10 * 1 mm Description The EM6521 is an advanced single chip CMOS 4-bit microcontroller. It contains EEPROM, RAM, LCD driver, power on reset, watchdog timer, oscillation detection circuit, 10-bit up/down and event counter, 1ms BCD counter, prescaler, voltage level detector (Vld), serial interface and several clock functions. The low voltage feature and low power consumption make it the most suitable controller for battery, stand alone and mobile equipment. The EM6521 is manufactured using EM Marin's Advanced Low Power (ALP) CMOS Process. Typical • • • • • • • • • Applications Timing device Automotive controls with display Intelligent display driver Measurement equipment Domestic appliance Interactive system with display Timer / sports timing devices Bicycle computers Safety and security devices Copyright © 2005, EM Microelectronic-Marin SA 1 www.emmicroelectronic.com R EM6521 EM6521 at a glance • Power Supply • 4-Bit Input Port A - Low voltage low power architecture including internal voltage regulator - 2.0 … 5.5 V battery voltage - 11 µA in active mode (Xtal, LCD on, 25 °C) - 1.8 µA in standby mode (Xtal, LCD off, 25 °C) - 0.1 µA in sleep mode (25 °C) - 32 KHz Oscillator - Direct input read on the port terminals - Debouncer function available on all inputs - Interrupt request on positive or negative edge - Pull resistor selectable by register - Test variables (software) for conditional jumps - PA[0] and PA[3] are inputs for the event counter - PA[3] is Start/Stop input for the millisecond counter - Reset with input combination • RAM - 64 x 4 bit, direct addressable - 64 x 4 bit, indexed addressable • EEPROM - 4096 x 16 bit, metal mask programmable • CPU - 4-bit RISC architecture - 2 clock cycles per instruction - 72 basic instructions • Main Operating Modes and Resets - Active mode (CPU is running) - Standby mode (CPU in halt) - Sleep mode (no clock, reset state) - Watchdog reset (logic and oscillation watchdogs) - Reset terminal and POR - Reset with input combination on port A (register selectable) • Liquid Crystal Display Driver (LCD) - 20 Segments 3 or 4 times multiplexed - Internal or external voltage multiplier - Free Segment allocation architecture - LCD switch off for power save • 8-Bit Serial Interface - 3 wire master/slave mode - READY output during data transfer - Maximum shift clock is equal to system clock - Interrupt request to the CPU after 8 bits - Supports different serial formats - Can be configured as a parallel 4 bit I/O port - Direct input read on the port terminals - All outputs can be put tristate (default) - Selectable pull resistors in input mode - CMOS or Nch. open drain outputs • Millisecond Counter - 3 digits binary coded decimal counter (12 bits) - PA[3] input pulse width and period measurement - Internal 1000 Hz clock generation - Hardware or software controlled start stop mode - Interrupt request on either 1/10 Sec or 1Sec Copyright © 2005, EM Microelectronic-Marin SA • 4-Bit Bi-directional Port B - All different functions bit-wise selectable - Direct input read on the port terminals - Data output latches - CMOS or Nch. open drain outputs - Pull-down or pull-up selectable - Selectable PWM, 32kHz, 1kHz and 1Hz output • Prescaler - 15 stage system clock divider down to 1Hz - 3 Interrupt requests; 1Hz, 32Hz or 8Hz, Blink - Prescaler reset (4kHz to 1Hz) • Voltage Level Detector (SVLD) - 8 different levels from 1.2 V to 4.0 V (ROM Version) - Busy flag during measure • 10-Bit Universal Counter - 10, 8, 6 or 4 bit up/down counting - Parallel load - Event counting (PA[0] or PA[3]) - 8 different input clocks - Full 10 bit or limited (8, 6, 4 bit) compare function - 2 interrupt requests (on compare and on 0) - Hi-frequency input on PA[3] and PA[0] - Pulse width modulation (PWM) output • Melody Generator - Dedicated Buzzer terminal - 7 tones plus silence output - The output can be put tristate (default) - Internal 4-bit timer, usable also in standalone mode - 4 different timer input clocks - Timer with automatic reload or single run - Timer interrupt request when reaching 0 • Interrupt Controller - 5 external and 8 internal interrupt request sources - Each interrupt request can individually be masked - Each interrupt flag can individually be reset - Automatic reset of each interrupt request after read - General interrupt request to CPU can be disabled - Automatic enabling of general interrupt request flag when going into HALT mode 2 www.emmicroelectronic.com R EM6521 Table of Contents Features Description Typical 2 3 4 5 6 1 Applications 1 5H 7 7 7 7 6H 7H 9H 8 9 10 10 10 11 11 1H 13H 14H 15H 16H 12 12 12 17H 18H 19H 14 14 15 20H 7.2 7.3 2H IRQ on Port A Pull-up or Pull-down Software Test Variables Port A for 10-Bit Counter and MSC 8.5.1 15 16 16 16 24H 25H 61H 62H 63H 64H 42 43 65H 6H 44 44 11 Supply Voltage Level Detector 11.1 SVLD Register 67H 68H 45 45 12 Strobe Output 12.1 Strobe Register 13 69H 70H 46 RAM 71H 14 LCD Driver 14.1 LCD Control 14.2 LCD Addressing 14.3 Free Segment Allocation 14.4 LCD Registers 47 48 48 49 49 72H 73H 74H 75H 76H 51 15 Peripheral Memory Map 16 Option Register Memory Map 17 Active Supply Current Test 7H 55 78H 56 79H 18 Mask Options 18.1 Input / Output Ports 18.1.1 18.1.2 18.1.3 18.1.4 18.1.5 18.1.6 16 18 27H 28H 18 19 19 20 29H 30H 31H 32H Port B Registers Port Serial 20 21 3H 34H 4-bit Parallel I/O Pull-up or Pull-down Nch. Open Drain Outputs General Functional Description Detailed Functional Description Output Modes Reset and Sleep on Port SP 21 22 23 23 24 24 25 35H 36H 37H 38H 39H 40H 41H Serial Interface Registers 26 42H 28 28 43H 4H Single Run Mode Continuos Run Mode 29 29 45H 46H Programming Order Melody Registers Copyright © 2005, EM Microelectronic-Marin SA 60H 10 Interrupt Controller 10.1 Interrupt Control Registers 26H Input / Output Mode Pull-up or Pull-down CMOS / NCH. Open Drain Output PWM and Frequency Output How the PWM Generator works. 59H 23H Port A Registers Port B 10-bit Counter 8.1 Full and Limited Bit Counting 8.2 Frequency Select and Up/Down Counting 8.3 Event Counting 8.4 Compare Function 8.5 Pulse Width Modulation (PWM) 38 38 38 39 39 41 Millisecond Counter 9.1 PA[3] Input for MSC 9.2 IRQ from MSC 9.3 MSC-Modes 9.4 Mode selection 9.5 Millisecond Counter Registers 21H Melody, Buzzer 7.1 4-Bit Timer 7.1.1 7.1.2 58H 12H Input and Output Ports 6.1 Ports Overview 6.2 Port A 6.7 35 56H 36 36 57H 10H Oscillator and Prescaler 5.1 Oscillator 5.2 Prescaler 6.6.1 6.6.2 6.6.3 6.6.4 6.6.5 6.6.6 6.6.7 PWM Characteristics Counter Setup 10-bit Counter Registers 8H Reset 4.1 Oscillation Detection Circuit 4.2 Reset Terminal 4.3 Input Port A Reset Function 4.4 Digital Watchdog Timer Reset 4.5 CPU State after Reset 6.5 6.6 8 4 6 4H Power Supply 6.4.1 6.4.2 6.4.3 6.4.4 7 2 3H Operating Modes 2.1 Active Mode 2.2 Standby Mode 2.3 Sleep Mode 6.3 6.4 9 2H Pin Description for EM6521 1.1 Programming Connections 6.2.1 6.2.2 6.2.3 6.2.4 8.6 8.7 1H EM6521 at a glance 1 8.5.2 1 0H 30 30 47H 48H 32 32 33 34 34 34 49H 50H 51H 52H 53H 57 57 80H 81H Port A Metal Options Port B Metal Options Port SP Metal Options Voltage Regulator Option Debouncer Frequency Option User defined LCD Segment Allocation 57 58 59 59 60 60 82H 83H 84H 85H 86H 19 Measured Electrical Behaviors 19.1 IDD Current 19.2 Regulator Voltage 19.3 Pull Resistors 19.4 Output currents 87H 61 61 61 61 62 8H 89H 90H 91H 92H 63 63 63 63 63 64 64 65 66 66 66 66 20 EM6521 Electrical Specification 20.1 Absolute Maximum Ratings 20.2 Handling Procedures 20.3 Standard Operating Conditions 20.4 DC Characteristics - Power Supply 20.5 Supply Voltage Level Detector 20.6 Oscillator 20.7 DC characteristics - I/O Pins 20.8 LCD SEG[20:1] Outputs 20.9 LCD Com[4:1] Outputs 20.10 DC Output Component 20.11 LCD Voltage Multiplier 21 93H 94H 95H 96H 97H 98H 9H 10H 10H 102H 103H 104H 67 Pad Location Diagram 105H 22 Package & Ordering information 22.1 Ordering Information 68 68 106H 107H 54H 35 5H 3 www.emmicroelectronic.com R EM6521 1 Pin Description for EM6521 Chip DIL 64 10 Signal Name Function Remarks 1 TQFP 52 1 VL1 Voltage multiplier level 1 2 2 11 VL2 Voltage multiplier level 2 3 3 12 VL3 Voltage multiplier level 3 LCD level 1 input, if external supply selected LCD level 2 input, if external supply selected LCD level 3 input, if external supply selected 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 13 14 15 16 18 19 20 21 22 23 26 27 28 29 30 31 33 34 35 36 37 38 39 42 43 COM[1] COM[2] COM[3] COM[4] SEG[20] SEG[19] SEG[18] SEG[17] SEG[16] SEG[15] SEG[14] SEG[13] SEG[12] SEG[11] SEG[10] SEG[9] SEG[8] SEG[7] SEG[6] SEG[5] SEG[4] SEG[3] SEG[2] SEG[1] Reset 29 29 44 Test LCD back plane 1 LCD back plane 2 LCD back plane 3 LCD back plane 4 LCD Segment 20 LCD Segment 19 LCD Segment 18 LCD Segment 17 LCD Segment 16 LCD Segment 15 LCD Segment 14 LCD Segment 13 LCD Segment 12 LCD Segment 11 LCD Segment 10 LCD Segment 9 LCD Segment 8 LCD Segment 7 LCD Segment 6 LCD Segment 5 LCD Segment 4 LCD Segment 3 LCD Segment 2 LCD Segment 1 Input reset terminal, internal pull-down 15 KOhm Input test terminal, internal pull-down 15 KOhm 30 30 45 PSP[0] 31 31 46 PSP[1] 32 32 47 PSP[2] 33 33 49 PSP[3] 34 34 50 PB[0] Copyright © 2005, EM Microelectronic-Marin SA Input/output , open drain serial port : SIN parallel out terminal 0 Output , open drain serial port : Ready/CS parallel out terminal 1 Output , open drain serial port : SOUT parallel out terminal 2 Input/output , open drain serial port : SCLK parallel out terminal 3 Input/output, open drain port B terminal 0 4 Not used if 3 times multiplexed Main reset For EM tests only, ground 0 ! Except when needed for MFP programming Serial interface data in or parallel data[0] in/out Serial interface Ready CS or parallel data[1] in/out Serial interface data out or parallel data[2] in/out Serial interface clock I/O or parallel data[3] in/out Port B data[0] I/O or Ck[1] output www.emmicroelectronic.com R EM6521 Chip DIL 64 51 Signal Name Function Remarks 35 TQFP 52 35 PB[1] 36 36 52 PB[2] 37 37 53 PB[3] 38 38 54 PA[0] Input/output, open drain port B terminal 1 Input/output, open drain port B terminal 2 Input/output, open drain port B terminal 3 Input port A terminal 0 39 40 41 39 40 41 55 58 59 PA[1] PA[2] PA[3] Input port A terminal 1 Input port A terminal 2 Input port A terminal 3 Port B data[1] I/O or Ck[11] output Port B data[2] I/O or Ck[16] output Port B data[3] I/O or PWM output TestVar 1 Event counter TestVar 2 TestVar 3 Event counter, MSC start/stop control 42 43 42 43 60 61 Buzzer Strobe Output Buzzer terminal Output Strobe terminal µP reset state or/and port B write or sleep flag out 44 44 62 VBAT = VDD Positive power supply MFP Connection 45 45 63 Vreg Internal voltage regulator Connect to minimum 100nF, MFP connection 46 46 64 Qin/Osc1 Crystal terminal 1 32 KHz crystal, MFP connection 47 47 2 Qout /Osc2 Crystal terminal 2 32 KHz crystal, MFP connection 48 48 3 VSS Negative power supply ref. terminal, MFP connection 49 49 4 C2B Voltage multiplier Not needed if ext. supply 50 50 5 C2A Voltage multiplier Not needed if ext. supply 51 51 6 C1B Voltage multiplier Not needed if ext. supply 52 52 7 C1A Voltage multiplier Not needed if ext. supply Gray shaded areas : Terminals needed for MFP programming connections (VDD, Vreg, Qin, Qout, Test). See also Programming connections. EM Microelectronic-Marin SA cannot assume responsibility for use of any circuitry described other than circuitry entirely embodied in an EM Microelectronic-Marin SA product. EM Microelectronic-Marin SA reserves the right to change the circuitry and specifications without notice at any time. You are strongly urged to ensure that the information given has not been superseded by a more up-to-date version. Copyright © 2005, EM Microelectronic-Marin SA 5 www.emmicroelectronic.com R EM6521 Figure 3. Typical Configuration L C D D is p la y C1 VL1 C1 VL2 C1 C O M [4 :1 ] A ll C a p a c ito rs 1 0 0 n F C rys ta l S E G [2 0 :1 ] Q in VL3 O out R eset C2 C 1A C 1B C2 C 2A C 2B EM 6521 V D D (V b a t) V re g P o rt A T e st C3 P o rt B P o rt S P 1.1 C4 VSS B u zz e r S tro b e Programming Connections The EM6521 can be programmed using the standard EM MFP programming box for 4 bit uControllers. The interface signals are listed in the table below. The circuit can be programmed on the programming box or directly on the PCB . For more information please refer to the MFP programmer’s manual. 29 TQFP 52 29 DIL 64 44 Signal Name Test 44 45 44 45 62 63 VBAT = VDD Vreg Function Input test terminal Internal pull-down 15k Positive power supply Internal voltage regulator 46 47 48 46 47 48 64 2 3 Qin/Osc1 Qout /Osc2 VSS Crystal terminal Crystal terminal Negative power supply Chip Copyright © 2005, EM Microelectronic-Marin SA 6 Remarks Usually 1 in MFP mode, 0 resets the MFP interface MFP Power Connection MFP power Connection, adapts the Oscillator voltage to VBAT MFP Serial Data Input / Output MFP serial Clock Input MFP Connection, Reference terminal www.emmicroelectronic.com R EM6521 2 Operating Modes The EM6521 has two low power dissipation modes, standby and sleep. these modes. 2.1 Figure 4 is a transition diagram for 108H Active Mode The active mode is the actual CPU running mode. Instructions are read from the internal ROM and executed by the CPU. Leaving active mode via the halt instruction to go into standby mode, the Sleep bit write to go into Sleep mode or a reset from port A to go into reset mode. 2.2 Standby Mode Executing a halt instruction puts the EM6521 into standby mode. The voltage regulator, oscillator, watchdog timer, LCD, interrupts, timers and counters are operating. However, the CPU stops since the clock related to instruction execution stops. Registers, RAM and I/O pins retain their states prior to standby mode. Standby is canceled by a reset or an interrupt request if enabled. 2.3 Figure 4 Mode transition diagram Active Halt instruction IRQ Standby Sleep Mode Sleep bit write Reset=1 Reset=0 Sleep Writing to the Sleep bit in the RegSysCntl1 register puts the EM6521 in sleep mode. Reset=1 Reset=1 The oscillator stops and most functions of the EM6521 are inactive. To be able to write to the Sleep bit, the SleepEn bit in Reset RegSysCntl2 must first be set to "1". In sleep mode only the voltage regulator and the reset input are active. The RAM data integrity is maintained. Sleep mode may be canceled only by a high level of min 10µs at the EM6521 Reset terminal or by the selected port A input reset combination, if option InpResSleep is turned on. Due to the cold-start characteristics of the oscillator, waking up from sleep mode may take some time to guarantee stable oscillation. During sleep mode and the following start up the EM6521 is in reset state. Waking up from sleep clears the Sleep flag but not the SleepEn bit. Inspecting the SleepEn allows to determine if the EM6521 was powered up (SleepEn = "0") or woken up from sleep (SleepEn = "1"). Table 2.3.1. Internal State in Standby and Sleep Mode Function Oscillator Oscillator Watchdog Instruction Execution Interrupt Functions Registers and Flags RAM Data Option Registers Timer & Counter Logic Watchdog I/O Port B and Serial Port Standby Active Active Stopped Active Retained Retained Retained Active Active Active Input Port A Active LCD Strobe Output Buzzer Output Voltage Level Detector Reset Pin Active Active Active Finishes ongoing measure, then stop Active Copyright © 2005, EM Microelectronic-Marin SA 7 Sleep Stopped Stopped Stopped Stopped Reset Retained Retained Reset Reset High Impedance, Pull’s as defined in option register No pull resistors and inputs deactivated except if InpResSleep = "1" Stopped (display off) Active High Impedance Stopped Active www.emmicroelectronic.com R EM6521 3 Power Supply The EM6521 is supplied by a single external power supply between VDD (VBAT) and VSS (Ground). A built-in voltage regulator generates Vreg providing regulated voltage for the oscillator and the internal logic. The output drivers are supplied directly from the external supply VDD. The internal power configuration is shown below in Figure 5. 109H Figure 5. Internal Power Supply T erm inal V bat M V reg M 1B 1kO hm M 1A A ll P ad input & output buffers, S V LD , EEPROM T erm inal V reg R ef. Logic C ore Logic,R A M , LC D Logic, O scillator V oltage m ultiplier, LC D outputs R ef. LC D Copyright © 2005, EM Microelectronic-Marin SA 8 www.emmicroelectronic.com R EM6521 4 Reset Figure 6. illustrates the reset structure of the EM6521. One can see that there are six possible reset sources : (1) Internal initial reset from the Power On Reset (POR) circuitry. --> POR (2) External reset from the Reset terminal. --> System Reset, Reset CPU (3) External reset by simultaneous high/low inputs to port A. --> System Reset, Reset CPU (Combinations are defined in the registers OptInpRSel1 and OptInpRSel2) (4) Internal reset from the Digital Watchdog. --> System Reset, Reset CPU (5) Internal reset from the Oscillation Detection Circuit. --> System Reset, Reset CPU (6) Internal reset when sleep mode is activated. --> System Reset, Reset CPU 10H All reset sources activate the System Reset and the Reset CPU. The ‘System Reset Delay’ ensures that the system reset remains active long enough for all system functions to be reset (active for n system clock cycles). The ‘CPU Reset Delay’ ensures that the reset CPU remains active until the oscillator is in stable oscillation. As well as activating the system reset and the reset CPU, the POR also resets all option registers and the sleep enable (SleepEn) latch. System reset and reset CPU do not reset the option registers nor the SleepEn latch. Reset state can be shown on Strobe terminal by selecting StrobeOutSel1,0 = 0 in RegLcdCntl1. Figure 6. Reset Structure Internal D ata Bus Digital W atchdog W rite R eset R ead Status Ck[1] W rite Active R ead Status SleepEn Sleep Latch Latch Inhibit D igital W atchdog C P U R eset D elay PO R Enable R eset C PU Activate PO R Ck[1] Analogue Filter DEBO U N CE C k[8] PO R PO R to O ption R egisters & SleepEn Latch O scillation D etection S ystem R eset D elay C k[15] Inhibit O scillation Detection C k[10] R eset PAD R eset from Port A Input Com bination O ptInpR Sleep Sleep Copyright © 2005, EM Microelectronic-Marin SA 9 www.emmicroelectronic.com R EM6521 4.1 Oscillation Detection Circuit At power on, the voltage regulator starts to follow the supply voltage and triggers the power on reset circuitry, and thus the system reset. The CPU of the EM6521 remains in the reset state for the ‘CPU Reset Delay’, to allow the oscillator to stabilize after power up. The oscillator is disabled during sleep mode. So when waking up from sleep mode, the CPU of the EM6521 remains in the reset state for the CPU Reset Delay, to allow the oscillator to stabilize. During this time, the Oscillation Detection Circuit is inhibited. In active or standby modes, the oscillator detection circuit monitors the oscillator. If it stops for any reason, a system reset is generated. After clock restart the CPU waits for the CPU Reset Delay before executing the first instructions. The oscillation detection circuitry can be inhibited with bit NoOscWD = 1 in register RegVldCntl. At power up, and after any system reset, the function is activated. The ‘CPU Reset Delay’ is 32768 system clocks ( Ck[16] ) long. 4.2 Reset Terminal During active or standby modes the Reset terminal has a debouncer to reject noise. Reset must therefore be active for at least 16 ms (system clock = 32 KHz). When canceling sleep mode, the debouncer is not active (no clock), however, reset passes through an analogue filter with a time constant of typical. 5µs. In this case Reset pin must be high for at least 10 µs to generate a system reset. 4.3 Input Port A Reset Function By writing the OptInpRSel1 and OptInpRSel2 registers it is possible to choose any combination of port A input values to execute a system reset. The reset condition must be valid for at least 16ms (system clock = 32kHz) in active and standby mode. OPTInpRSleep selects the input port A reset function in sleep mode. If set to "1" the occurrence of the selected combination for input port A reset will immediately trigger a system reset (no debouncer) . Reset combination selection (InpReset) is done with registers OptInpRSel1 and OptInpRSel2. Following formula is applicable : InpResPA = InpResPA[0] • InpResPA[1] • InpResPA[2] • InpResPA[3] Figure 7. Input Port A Reset Structure InpRes1PA[n] 0 0 1 1 n = 0 to 3 InpRes2PA[n] 0 1 0 1 InpResPA[n] VSS PA[n] not PA[n] VDD i.e. ; - no reset if InpResPA[n] = VSS. - Don't care function on a single bit with its InpResPA[n] = VDD. - Always Reset if InpResPA[3:0] = 'b1111 BIT [0] Input Port A Reset Bit[0] Selection BIT [1] Input Port A Reset Bit[1] Selection BIT [2] Input Port A Reset Bit[2] Selection BIT InpRes1PA[3] [3] InpRes2PA[3] VSS PA[3] PA[3] VDD 0 1 MUX 2 3 1 0 InpResPA Input Reset from Port A InpResPA[3] Input Port A Reset Bit[3] Selection Copyright © 2005, EM Microelectronic-Marin SA 10 www.emmicroelectronic.com R EM6521 4.4 Digital Watchdog Timer Reset The digital watchdog is a simple, non-programmable, 2-bit timer, that counts on each rising edge of Ck[1]. It will generate a system reset if it is not periodically cleared. The watchdog timer function can be inhibited by activating an inhibit digital watchdog bit (NoLogicWD) located in RegVldCntl. At power up, and after any system reset, the watchdog timer is activated. If for any reason the CPU stops, then the watchdog timer can detect this situation and activate the system reset signal. This function can be used to detect program overrun, endless loops, etc. For normal operation, the watchdog timer must be reset periodically by software at least every 2.5 seconds (system clock = 32 KHz), or a system reset signal is generated. The watchdog timer is reset by writing a ‘1’ to the WDReset bit in the timer. This resets the timer to zero and timer operation restarts immediately. When a ‘0’ is written to WDReset there is no effect. The watchdog timer operates also in the standby mode and thus, to avoid a system reset, one should not remain in standby mode for more than 2.5 seconds. From a system reset state, the watchdog timer will become active after 3.5 seconds. However, if the watchdog timer is influenced from other sources (i.e. prescaler reset), then it could become active after just 2.5 seconds. It is therefore recommended to use the Prescaler IRQHz1 interrupt to periodically reset the watchdog every second. It is possible to read the current status of the watchdog timer in RegSysCntl2. After watchdog reset, the counting sequence is (on each rising edge of CK[1]) : ‘00’, ‘01’, ‘10’, ‘11’ {WDVal1 WDVal0}. When going into the ‘11’ state, the watchdog reset will be active within ½ second. The watchdog reset activates the system reset which in turn resets the watchdog. If the watchdog is inhibited it’s timer is reset and therefore always reads ‘0’. Table 4.4.1 Watchdog Timer Register RegSysCntl2 Bit 3 Name WDReset Reset 0 R/W R/W 2 1 0 SleepEn WDVal1 WDVal0 0 0 0 R/W R R 4.5 Description Reset the Watchdog 1 -> Resets the Logic Watchdog 0 -> No action The Read value is always '0' See Operating modes (sleep) Watchdog timer data Ck[1] divided by 4 Watchdog timer data Ck[1] divided by 2 CPU State after Reset Reset initializes the CPU as shown in Table 4.5.1 below. 1H Table 4.5.1 Initial CPU Value after Reset. Name Bits Program counter 0 12 Program counter 1 12 Program counter 2 12 Stack pointer 2 Index register 7 Carry flag 1 Zero flag 1 Halt 1 Instruction register 16 Periphery registers Copyright © 2005, EM Microelectronic-Marin SA 4 Symbol PC0 PC1 PC2 SP IX CY Z HALT IR Initial Value hex 000 (as a result of Jump 0) Undefined Undefined PSP[0] selected Undefined Undefined Undefined 0 Jump 0 Reg. See peripheral memory map 11 www.emmicroelectronic.com R EM6521 5 5.1 Oscillator and Prescaler Oscillator A built-in crystal oscillator generates the system operating clock for the CPU and peripheral blocks, from an externally connected crystal (typically 32.768kHz). The oscillator circuit is supplied by the regulated voltage, Vreg. In sleep mode the oscillator is stopped. EM’s special design techniques guarantee the low current consumption of this oscillator. The external impedance between the oscillator pads must be greater than 10MOhm. Connection of any other components to the two oscillator pads must be confirmed by EM Microelectronic-Marin SA. 5.2 Prescaler The prescaler consists of fifteen elements divider chain which delivers clock signals for the peripheral circuits such as timer/counter, buzzer, LCD voltage multiplier, debouncer and edge detectors, as well as generating prescaler interrupts. The input to the prescaler is the system clock signal. Power on initializes the prescaler to Hex(0001). Table 5.2.1 Prescaler Clock Name Definition Function System clock System clock / 2 System clock / 4 System clock / 8 System clock/ 16 System clock / 32 System clock / 64 System clock / 128 Name Ck[16] Ck[15] Ck[14] Ck[13] Ck[12] Ck[11] Ck[10] ck [9] 32 KHz Xtal 32768 Hz 16384 Hz 8192 Hz 4096 Hz 2048 Hz 1024 Hz 512 Hz 256 Hz Function System clock / 256 System clock / 512 System clock / 1024 System clock / 2048 System clock / 4096 System clock / 8192 System clock / 16384 System clock / 32768 1 0 Name PWMOn ResPresc PrIntSel DebSel Reset 0 0 0 0 R/W R/W R/W R/W R/W 32 KHz Xtal 128 Hz 64 Hz 32 Hz 16 Hz 8 Hz 4 Hz 2 Hz 1 Hz Figure 8. Prescaler Frequency Timing Table 5.2.2 Control of Prescaler Register RegPresc Bit 3 2 Name Ck[8] Ck[7] Ck[6] Ck[5] Ck[4] Ck[3] Ck[2] Ck[1] Description see 10 bit counter Write Reset prescaler 1 -> Resets the divider chain from Ck[14] down to Ck[2], sets Ck[1]. 0 -> No action. Prescaler Reset System Clock Ck[16] Ck[15] Ck[14] The Read value is always '0' Interrupt select. 0 -> Interrupt from Ck[4] 1 -> Interrupt from Ck[6] Debouncer clock select. 0 -> Debouncer with Ck[8] 1 -> Debouncer with Ck[11] or Ck[14], see below Horizontal Scale Change Ck[2] Ck[1] First positive edge of 1 Hz clock is 1s after the falling reset edge With DebSel = 1 one may choose either the Ck[11] or Ck[14] debouncer frequency by selecting the corresponding metal mask option (for ROM version only). Relative to 32kHz the corresponding max. debouncer times are then 2 ms or 0.25 ms. For the metal mask selection refer to chapter 18.1.5. 12H Switching the PrIntSel may generate an interrupt request. Avoid it with MaskIRQ32/8 = 0 selection during the switching operation. Copyright © 2005, EM Microelectronic-Marin SA 12 www.emmicroelectronic.com R EM6521 The prescaler contains 3 interrupt sources: Figure 9. Prescaler Interrupts - IRQ32/8 ; this is Ck[6] or Ck[4] positive edge interrupt, the selection is depending on bit PrIntSel. - IRQHz1 ; this is Ck[1] positive edge interrupt Ck[2] - IRQBlink ; this is 3/4 of Ck[1] period interrupt Ck[1] There is no interrupt generation on reset. IRQ Hz1 The first IRQHz1 Interrupt occurs 1 sec (32kHz) after reset. IRQBlink A possible application for the IRQBlink is LCD-Display blinking control together with IRQHz1. Copyright © 2005, EM Microelectronic-Marin SA 13 www.emmicroelectronic.com R EM6521 6 Input and Output Ports The EM6521 has: - One 4-bit input port ( port A ) - One 4-bit input/output port. ( port B ) - One serial interface (port SP) also configurable as 4-bit I/O port Pull resistors can be added to all this ports with metal (ROM version only) and/or register options. 6.1 Ports Overview Table 6.1.1 Input and Output Ports Overview Port Mode PA [3:0] Input PB [3:0] PS [3:0] Mask(M:) or Register(R:) Option M: Pull-up M: Pull-down (default) R: Pull(up/down) select R: Debouncer or direct input for IRQ requests and Counter R: + or - for IRQ-edge and counter R: Input reset combination Function Individual input or output R: CMOS or Nch. open drain output R: Pull-down on input R: Pull-up on input Serial I/O or port-wise input / output R: CMOS or Nch open drain output R: Pull-down on input R: Pull-up on input -Input or output -PB[3] for the PWM output -PB[2:0] for the Ck[16,11,1] output -Tristate output -PSP[3], serial clock out -PSP[2], serial data out -PSP[1], serial status out -PSP[0], serial data in -PSP[3:0] 4-bit input/output -Tristate output Copyright © 2005, EM Microelectronic-Marin SA Bit-wise Multifunction on Ports -Input -Bit-wise interrupt request -Software test variable conditional jump -PA[3],PA[0] input for the event counter -PA[3] input for the millisecond counter -Port A reset inputs 14 PA[3] PA[2] PA[1] - - start/stop of MSC - - - PB[3] PB[2] PB[1] PB[0] PWM output Ck[16] output Ck[11] output Ck[1] output PSP[3] PSP[2] PSP[1] PSP[0] Serial clock output Serial data output Ready or CS Serial data input SCLK SOUT Ready/CS SIN 10 bit event counter clock PA[0] 10 bit event counter clock www.emmicroelectronic.com R EM6521 6.2 Port A The EM6521 has one four bit general purpose CMOS input port. The port A input can be read at any time, internal pull-up or pull-down resistors can be chosen by metal mask (for ROM version only). All selections concerning port A are bit-wise executable. I.e. Pull-up on PA[2], pull-down on PA[0], positive IRQ edge on PA[0] but negative on PA[1], etc. In sleep mode the port A pull-up or pull-down resistors are turned off, and the inputs are deactivated except if the InpResSleep bit in the option register OPTFSel is set to 1. In this case the port A inputs are continuously monitored to match the input reset condition which will immediately wake the EM6521 from sleep mode (all pull resistors remain). Figure 10. Input Port A Configuration NoDebIntPA[n]=1 Vbat (VDD) IntEdgPA[n]=0 PA3 for the Millisecond Counter Mask opt MPAPU[n] IRQPA[3:0] PA[n]terminal PA0, PA3 for 10-Bit Counter Debouncer Mask opt MPAPD[n] µP TestVar Ck[8] Ck[11] or Ck[14] DB[3:0] Input Reset allowed when in Sleep Sleep VSS NoPullPA[n] 6.2.1 IRQ on Port A For interrupt request generation (IRQ) one can choose direct or debouncer input and positive or negative edge IRQ triggering. With the debouncer selected ( OPTDebIntPA ) the input must be stable for two rising edges of the selected debouncer clock (RegPresc). This means a worst case of 16 ms (default) or 2 ms (0.25 ms by metal mask, for ROM Version only) with a system clock of 32 KHz. Either a positive or a negative edge on the port A inputs - after debouncer or not - can generate an interrupt request. This selection is done in the option register OPTIntEdgPA. All four bits of port A can provide an IRQ, each pin with its own interrupt mask bit in the RegIRQMask1 register. When an IRQ occurs, inspection of the RegIRQ1, RegIRQ2 and RegIRQ3 registers allows the interrupt to be identified and treated. At power on or after any reset the RegIRQMask1 is set to 0, thus disabling any input interrupt. A new interrupt is only stored with the next active edge after the corresponding interrupt mask is cleared. See also the interrupt chapter 10. It is recommended to mask the port A IRQ’s while one changes the selected IRQ edge. Else one may generate a IRQ (Software IRQ). I.e. PA[0] on ‘0’ then changing from positive to negative edge selection on PA[0] will immediately trigger an IRQPA[0] if the IRQ was not masked. 13H Copyright © 2005, EM Microelectronic-Marin SA 15 www.emmicroelectronic.com R EM6521 6.2.2 Pull-up or Pull-down Each of the input port terminals PA[3:0] has a resistor integrated which can be used either as pull-up or pulldown resistor, depending on the selected metal mask options( ROM version only). See the port A metal mask chapter for details. The pull resistor can be inhibited using the NoPullPA[n] bits in the register OptNoPullPA. Table 6.2.1. Pull-up or Pull-down Resistor on Port A Inputs Option mask Option mask NoPullPA[n] pull-up pull-down value Action MPAPU[n] MPAPD[n] no no x no pull-up, no pull-down no yes 0 no pull-up, pull-down no yes 1 no pull-up, no pull-down yes no 0 pull-up, no pull-down yes no 1 no pull-up , no pull-down yes yes x not allowed* with n=0…3 * only pull-up or pull-down may be chosen on any port A terminal (one choice is excluding the other) 6.2.3 Software Test Variables The port A terminals PA[2:0] are also used as input conditions for conditional software branches. Independent of the OPTDebIntPA and the OPTIntEdgPA. These CPU inputs always have a debouncer. - Debounced PA[0] is connected to CPU TestVar1. - Debounced PA[1] is connected to CPU TestVar2. - Debounced PA[2] is connected to CPU TestVar3. 6.2.4 Port A for 10-Bit Counter and MSC The PA[0] and PA[3] inputs can be used as the clock input terminal for the 10 bit counter in "event count" mode. As for the IRQ generation one can choose debouncer or direct input with the register OPTDebIntPA and non-inverted or inverted input with the register OPTIntEdgPA. Debouncer input is always recommended. Pad input PA[3] is also used as start/stop control for the millisecond counter. This control signal is derived from PA[3], it is independent of the port A debouncer and edge selection. Refer also to Figure 10. 14H 6.3 Port A Registers Table 6.3.1 Register RegPA Bit Name Reset 3 PAData[3] 2 PAData[2] 1 PAData[1] 0 PAData[0] * Direct read on port A terminals Copyright © 2005, EM Microelectronic-Marin SA R/W R* R* R* R* Description PA[3] input status PA[2] input status PA[1] input status PA[0] input status 16 www.emmicroelectronic.com R EM6521 Table 6.3.2 Register RegIRQMask1 Bit Name Reset R/W Description 3 MaskIRQPA[3] 0 R/W Interrupt mask for PA[3] input 2 MaskIRQPA[2] 0 R/W Interrupt mask for PA[2] input 1 MaskIRQPA[1] 0 R/W Interrupt mask for PA[1] input 0 MaskIRQPA[0] 0 R/W Interrupt mask for PA[0] input Default "0" is: interrupt request masked, no new request stored Table 6.3.3 Register RegIRQ1 Bit Name Reset R/W Description 3 IRQPA[3] 0 R/W* Interrupt request on PA[3] 2 IRQPA[2] 0 R/W* Interrupt request on PA[2] 1 IRQPA[1] 0 R/W* Interrupt request on PA[1] 0 IRQPA[0] 0 R/W* Interrupt request on PA[0] *; Write "1" clears the bit, write "0" has no action, default "0" is: no interrupt request Table 6.3.4 Register OPTIntEdgPA Bit Name power on value 3 IntEdgPA[3] 0 2 IntEdgPA[2] 0 1 IntEdgPA[1] 0 0 IntEdgPA[0] 0 Default "0" is: Positive edge selection R/W Description R/W R/W R/W R/W Interrupt edge select for PA[3] Interrupt edge select for PA[2] Interrupt edge select for PA[1] Interrupt edge select for PA[0] Table 6.3.5 Register OPTDebIntPA Bit Name power on R/W value 3 NoDebIntPA[3] 0 R/W 2 NoDebIntPA[2] 0 R/W 1 NoDebIntPA[1] 0 R/W 0 NoDebIntPA[0] 0 R/W Default "0" is: Debounced inputs for interrupt generation Description Interrupt debounced for PA[3] Interrupt debounced for PA[2] Interrupt debounced for PA[1] Interrupt debounced for PA[0] Table 6.3.6 Register OPTNoPullPA Bit Name power on value 3 NoPullPA[3] 0 2 NoPullPA[2] 0 1 NoPullPA[1] 0 0 NoPullPA[0] 0 Default "0" depending on mask selection Copyright © 2005, EM Microelectronic-Marin SA R/W Description R/W R/W R/W R/W Pull-up/down selection on PA[3] Pull-up/down selection on PA[2] Pull-up/down selection on PA[1] Pull-up/down selection on PA[0] 17 www.emmicroelectronic.com R EM6521 6.4 Port B The EM6521 has one four bit general purpose I/O port. Each bit can be configured individually by software for input/output, pull-up, pull-down and CMOS or Nch. open drain output type. The port outputs either data, frequency or PWM signals. 6.4.1 Input / Output Mode Each port B terminal is bit-wise bi-directional. The input or output mode on each port B terminal is set by writing the corresponding bit in the RegPBCntl control register. To set for input (default), 0 is written to the corresponding bit of the RegPBCntl register which results in a high impedance state for the output driver. The output mode is set by writing 1 in the control register, and consequently the output terminal follows the status of the bits in the RegPBData register. The port B terminal status can be read on address RegPBData even in output mode. Be aware that the data read on port B is not necessary of the same value as the data stored on RegPBData register. See also Figure 11 for details. 15H Figure 11. Port B Architecture Pull-down Option Register Internal Data Bus Open Drain Option Register OD[n] Pd[n] Port B Direction Register DDR[n] Port B Control Read Port B Data Register DR[n] MUX PB[n] Active Pull-up in Nch. Open Drain Mode Mask Option MPBPD[n] I / O Terminal Multiplexed Outputs are: PWM, Ck[16], Ck[11], Ck[1] Multiplexed Output mask option MPBPD[n] Multiplexed Output Active 4 Read Active Pull-down DB[n] Read for PB[3:0] Copyright © 2005, EM Microelectronic-Marin SA 18 www.emmicroelectronic.com R EM6521 6.4.2 Pull-up or Pull-down On each terminal of PB[3:0] an internal input pull-up (metal mask MPBPU[n]) or pull-down (metal mask MPBPD[n]) resistor can be connected per metal mask option (ROM version only). Per default the two resistors are in place. In this case one can chose per software to have either a pull-up, a pull-down or no resistor. See below. For Metal mask selection and available resistor values refer to chapter 0. 16H Pull-down ON : MPBPD[n] must be in place , AND bit NoPdPB[n] must be ‘0’ . Pull-down OFF: MPBPD[n] is not in place, OR if MPBPD[n] is in place NoPdPB[n] = ‘1’ cuts off the pull-down. OR selecting NchOpDPB[n] = ‘1’ cuts off the pull-down. Pull-up ON * : MPBPU[n] must be in place, AND bit NchOpDPB[n] must be ‘1’ , AND (bit PBIOCntl[n] = ‘0’ (input mode) OR if PBIOCntl[n] = ‘1’ while PBData[n] = 1. ) Pull-up OFF* : MPBPU[n] is not in place, OR if MPBPU[n] is in place NchOpDPB[n] = ‘0’ cuts off the pull-up, OR if MPBPU[n] is in place and if NchOpDPB[n] = ‘1’ then PBData[n] = 0 cuts off the pull-up. Never pull-up and pull-down can be active at the same time. For POWER SAVING one can switch off the port B pull resistors between two read phases. No cross current flows in the input amplifier while the port B is not read. The recommended order is : • Switch on the pull resistor. • Allow sufficient time - RC constant - for the pull resistor to drive the line to either VSS or VDD. • Read the port B • Switch off the pull resistor Minimum time with current on the pull resistor is 4 system clock periods, if the RC time constant is lower than 1 system clock period. Adding a NOP instruction before reading moves the number of periods with current in the pull resistor to 6 and the maximum RC delay to 3 clock periods. 6.4.3 CMOS / NCH. Open Drain Output The port B outputs can be configured as either CMOS or Nch. open drain outputs. In CMOS both logic ‘1’ and ‘0’ are driven out on the terminal. In Nch. Open Drain only the logic ‘0’ is driven on the terminal, the logic ‘1’ value is defined by the internal pull-up resistor (if implemented), or high impedance. Figure 12. CMOS or Nch. Open Drain Outputs N c h . O p e n D ra in O u tp u t C M O S O u tp u t A c tiv e P u llu p fo r H ig h S ta te MUX D R [n ] F re q u e n c y O u tp u ts 1 D a ta I / O T e rm in a l P B [n ] T ri-S ta te O u tp u t B u ffe r : c lo s e d Copyright © 2005, EM Microelectronic-Marin SA MUX I / O T e rm in a l D R [n ] F re q u e n c y O u tp u ts 19 T ri-S ta te O u tp u t B u ffe r : H ig h Im p e d a n c e fo r D a ta = 1 P B [n ] www.emmicroelectronic.com R EM6521 6.4.4 PWM and Frequency Output PB[3] can also be used to output the PWM (Pulse Width Modulation) signal from the 10-Bit Counter, the Ck[16], Ck[11] as well as the Ck[1] prescaler frequencies. -Selecting PWM output on PB[3] with bit PWMOn in register RegPresc and running the counter. -Selecting Ck[16] output on PB[2] with bit PB32kHzOut in register OPTFSelPB -Selecting Ck[11] output on PB[1] with bit PB1kHzOut in register OPTFSelPB -Selecting Ck[1 ] output on PB[0] with bit PB1HzOut in register OPTFSelPB 6.5 Port B Registers Table 6.5.1 Register RegPBData Bit Name Reset R/W 3 PBData[3] R*/W 2 PBData[2] R*/W 1 PBData[1] R*/W 0 PBData[0] R*/W * : Direct read on the port B terminal (not the internal register) Description PB[3] input and output PB[2] input and output PB[1] input and output PB[0] input and output Table 6.5.2 Register RegPBCntl Bit Name Reset 3 PBIOCntl[3] 0 2 PBIOCntl[2] 0 1 PBIOCntl[1] 0 0 PBIOCntl[0] 0 Default "0" is: port B in input mode R/W R/W R/W R/W R/W Description I/O control for PB[3] I/O control for PB[2] I/O control for PB[1] I/O control for PB[0] Table 6.5.3 Option Register OPTFSelPB Bit Name power on R/W Description value 3 InpResSleep 0 R/W Reset from sleep with port A 2 PB32kHzOut 0 R/W Ck[16] output on PB[2] 1 PB1kHzOut 0 R/W Ck[11] output on PB[1] 0 PB1HzOut 0 R/W Ck[1] output on PB[0] Default "0" is: No frequency output, port A Input Reset can not reset the SLEEP mode. Table 6.5.4 Option Register OPTNoPdPB Bit 3 2 1 0 Name NoPdPB[3] NoPdPB[2] NoPdPB[1] NoPdPB[0] Default "0" is: Pull-down on power on value 0 0 0 0 R/W Description R/W R/W R/W R/W No pull-down on PB[3] No pull-down on PB[2] No pull-down on PB[1] No pull-down on PB[0] R/W Description R/W R/W R/W R/W Nch. Open Drain on PB[3] Nch. Open Drain on PB[2] Nch. Open Drain on PB[1] Nch. Open Drain on PB[0] Table 6.5.5 Option Register OPTNchOpDPB Bit 3 2 1 0 Name NchOpDPB[3] NchOpDPB[2] NchOpDPB[1] NchOpDPB[0] Default "0" is: CMOS output power on value 0 0 0 0 Copyright © 2005, EM Microelectronic-Marin SA 20 www.emmicroelectronic.com R EM6521 6.6 Port Serial The EM6521 contains a simple, half duplex three wire synchronous type serial interface., which can be used to program or read an external EEPROM, ADC, ... etc. For data reception, a shift-register converts the serial input data on the SIN(PSP[0]) terminal to a parallel format, which is subsequently read by the CPU in registers RegSDataL and RegSDataH for low and high nibble. To transmit data, the CPU loads data into the shift register, which then serializes it on the SOUT(PSP[2]) terminal. It is possible for the shift register to simultaneously shift data out on the SOUT terminal and shift data on the SIN terminal. In Master mode, the shifting clock is supplied internally by the Prescaler : one of three prescaler frequencies are available, Ck[16], Ck[15] or Ck[14]. In Slave mode, the shifting clock is supplied externally on the SCLKIn(PSP[3]) terminal. In either mode, it is possible to program : the shifting edge, shift MSB first or LSB first and direct shift output. All these selection are done in register RegSCntl1 and RegSCntl2. Figure 13. Serial Interface Architecture Serial Master Clock Output SCLKOut to SCLK Terminal Serial Input Data from SIN terminal Internal Master Clock Source (from Prescaler) External Slave Clock Source (SCLKIn from SCLK terminal) M U X Mode 8 Bit Shift Register Shift CK Clock Enable Write Tx Read Rx Shift Complete (8th Shift Clock) High-Z to all SP[3:0] Terminals Start Direct MSB/LSB Control & Status Registers Status Reset Shift Start Serial Output Data to SOUT Terminal IRQSerial Status to CS/ Ready Terminal First Control Logic 4-Bit Internal Data Bus The PSP[3..0] terminal configuration is shown in Figure 14. When the Serial Interface is active then : 17H ∗ ∗ ∗ ∗ PSP[1] {Ready / CS) is outputting the ready (slave mode) or the CS signal (master mode). PSP[2] {SOUT} is always an output. PSP[0] {SIN} is always an input. PSP[3] {SCLK} is an output for Master mode {SCLKOut} and an input for Slave mode {SCLKIn} 6.6.1 4-bit Parallel I/O Selecting OM[1],OM[0] = ‘1’ in register RegSCntl2 the PSP[3:0] terminals are configured as a 4-bit Output. Output data is stored in the register RegSPData . The RegSPData is defined as a read/write register, but what is read is not the register output, but the port PSP[3:0] terminal values Selecting OM[1],OM[0] = ‘0’ in register RegSCntl2 the PSP[3:0] outputs are cut off (tristate). The terminals can be used as inputs with individual (bit-wise) pull-up or pull-down settings. Independent of the selected configuration, the PSP[3:0] terminal levels are always readable. Copyright © 2005, EM Microelectronic-Marin SA 21 www.emmicroelectronic.com R EM6521 Figure 14. Port SP Terminal Configuration Mode (direction for SCLKOut Terminal only) Internal Data Bus Read Parallel Output Data Register Tristate Pull-down Option Register Nch. Open Drain Option Register Pd[n] OD[n] Serial / Parallel Control DR[n] Active Pull-up in Nch. Open Drain Mode Mask Option MPSPU[n] MUX I / O Terminal Serial Interface Outputs (SOUT, Ready/CS and SCLK) SP[n] Mask Option MPSPD[n] Parallel Output Read DB[n] Serial Interface Inputs (SIN and SCLKIn) Active Pulldown Read OR Serial Mode 6.6.2 Pull-up or Pull-down For each terminal of PSP[3:0] an input pull-up (metal mask MPSPU[n]) or pull-down (metal mask MPSPD[n]) resistor can be implemented per metal mask option (ROM version only). Per default the two metal masks are in place, so one can chose per software to have either a pull-up, a pull-down or no resistor. For Metal mask selection and available resistor values refer to chapter Error! Reference source not found. Pull-down ON : MPSPD[n] must be in place , AND the bit NoPdPS[n] must be ‘0’ . Pull-down OFF: MPSPD[n] is not in place, OR if MPSPD[n] is in place NoPdPS[n] = ‘1’ cuts off the pull-down. OR selecting NchOpDPS[n] = ‘1’ cuts off the pull-down. Pull-up ON * : MPSPU[n] must be in place, AND the bit NchOpDPS[n] must be ‘1’ , AND ( the bits OM[1,0] in RegSysCntl2 = ‘00’ (input mode) OR any of the port SP terminals is in output mode with a logic ‘1’ to be driven) . Pull-up OFF* : MPSPU[n] is not in place, OR if MPSPU[n] is in place NchOpDPS[n] = ‘0’ cuts off the pull-up, OR if MPSPU[n] is in place and NchOpDPS[n] = ‘1’ then SerPData[n] = 0 cuts off the pull-up. Copyright © 2005, EM Microelectronic-Marin SA 22 www.emmicroelectronic.com R EM6521 For POWER SAVING one can switch off the port SP pull resistors between two read phases. No cross current flows in the input amplifier while the port SP is not read. This power saving feature must only be used in tristate mode (OM[0,1]=0). The recommended order is : • switch on the pull resistor. • allow sufficient time - RC constant - for the pull resistor to drive the line to either VSS or VDD. • Read the port SP • Switch off the pull resistor Minimum time with current on the pull resistor is 4 periods of the system clock, if the RC constant is lower than 1 system clock period. Adding a NOP before reading moves the number of periods with current in the pull resistor to 6 and the maximum RC delay to 3 clock periods. 6.6.3 Nch. Open Drain Outputs The port SP outputs can be configured as either CMOS or Nch. open drain outputs. In CMOS both logic ‘1’ and ‘0’ are driven out on the terminal. In Nch. open drain only the logic ‘0’ is driven out on the terminal, the logic ‘1’ value is high impedance or defined by the internal pull-up resistor (if existing). Figure 15. CMOS or Nch. Open Drain outputs Nch. Open Drain Output CMOS Output Active Pull-up for High State MUX DR[n] Serial Interface Output 1 Data I/O Term inal SP[n] Tristate Output Buffer : closed MUX I/O Term inal DR[n] Serial Interface Output Data Tristate Output Buffer : High Im pedance for Data = 1 SP[n] 6.6.4 General Functional Description After power on or after any reset the serial interface is in serial slave mode with Start and Status set to 0, LSB first, negative shift edge and all outputs are in high impedance state. When the Start bit is set, the shift operation is enabled and the serial interface is ready to transmit or receive data, eight shift operations are performed: 8 serial data values are read from the data input terminal into the shift register and the previous loaded 8-bits are send out via the data output terminal. After the eight shift operation, an interrupt is generated, and the Start bit is reset. Parallel to serial conversion procedure ( master mode example ). Write to RegSCntl1 serial control (clock freq. in master mode, edge and MSB/LSB select). Write to RegSDataL and RegSDataH (shift out data values). Write to RegSCntl2 (Start=1, mode select, status). ---> Starts the shift out After the eighth clock an interrupt is generated, Start becomes low. Then, interrupt handling Serial to parallel conversion procedure (slave mode example). Write to RegSCntl1 (slave mode, edge and MSB/LSB select). Write to RegSCntl2 (Start=1, mode select, status). After eight serial clocks an interrupt is generated, Start becomes low. Interrupt handling. Shift register RegSDataL and RegSDataH read. A new shift operation can be authorized. Copyright © 2005, EM Microelectronic-Marin SA 23 www.emmicroelectronic.com R EM6521 6.6.5 Detailed Functional Description Master or Slave mode is selected in the control register RegSCntl1. In Slave mode, the serial clock comes from an external device and is input via the PSP[3] terminal as a synchronous clock (SCLKIn) to the serial interface. The serial clock is ignored as long as the Start bit is not set. After setting Start, only the eight following active edges of the serial clock input PSP[3] are used to shift the serial data in and out. After eight serial clock edges the Start bit is reset. The PSP[1] terminal is a copy of the (Start OR Status) bit values, it can be used to indicate to the external master, that the interface is ready to operate or it can be used as a chip select signal in case of an external slave. In Master mode, the synchronous serial clock is generated internally from the system clock. The frequency is selected from one out of three sources ( MS0 and MS1 bits in RegSCntl1) . The serial shifting clock is only generated during Start = high and is output to the SCLK terminal as the Master Clock (SCLKOut). When Start is low, the serial clock output on PSP[3] is 0. An interrupt request IRQSerial is generated after the eight shift operations are done. This signal is set by the last negative edge of the serial interface clock on PSP[3] (master or slave mode) and is reset to 0 by the next write of Start or by any reset. This interrupt can be masked with register RegIRQMask3. For more details about the interrupt handling see chapter 10. Serial data input on PSP[0] is sampled by the positive or negative serial shifting clock edge, as selected by the Control Register POSnNeg bit. Serial data input is shifted in LSB first or MSB first, as selected by the Control Register MSBnLSB bit. 18H 6.6.6 Output Modes Serial data output is given out in two different ways (Refer also to - OM[1] = 1, OM[0] = 0 : The serial output data is generated with the selected shift register clock (POSnNeg). The first data bit is available directly after the Start bit is set. 19H Figure 16 and Figure 17). 120H Figure 16. Direct or Re-Synchronized Output SIN bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 Direct Shift Out +ve/-ve Edge -OM[1] = 0, OM[0] = 1 : The serial output data is re-synchronized by the positive serial interface clock edge, independent of the selected clock shifting edge. The first data bit is available on the first positive serial interface clock edge after Start=‘1’. SOUT M U X MSBnLSB SIN bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 +ve/-ve Edge M U X SOUT bit[n ] Re-synchronised shift out +ve Edge clock Table 6.6.6 Output Mode Selection in RegSCntl2 OM[1] OM[0] Output mode Description 0 0 Tristate Output disable (tristate on PSP[3:0]) 0 1 SerialSynchronized Re-synchronized positive edge data shift out 1 0 Serial-Direct Direct shift pos. or neg. edge data out 1 1 Parallel Parallel port SP output Tristate output is selected by default. Copyright © 2005, EM Microelectronic-Marin SA 24 www.emmicroelectronic.com R EM6521 Figure 17 Shift Operation and IRQ Generation SCLK = System Clock; Active Edge = Neg. Edge; Sense = MSB First Clock Source Shift Ck Start IRQ Shift Register 10010011 01001100 0 SIN 1 0 0 1 1 0 0 0 1 1 OM[1]=0, OM[0]=1 : Re-Synchronized on positive SCLK clock edge data out 1 SOUT 0 0 1 0 OM[1]=1, OM[0]=0 : direct data out on pos. or neg. SCLK clock edge depending on bit POSnNeg SOUT 1 0 0 1 0 0 1 1 6.6.7 Reset and Sleep on Port SP During circuit initialization, all option registers are reset by Power On Reset and therefore all pull-ups are off and all pull-downs are on. During Sleep mode, Port SP inputs are cut-off , the circuit is in Reset State. However the Reset State does not reset the option registers and pull-downs, if previously turned on, remain on even during Sleep mode. After any reset the serial interface parameters are reset to : Slave mode, Start and Status = 0, LSB first, negative edge shift , PSP[3:0] tristate. Note : A write operation in the control registers or in the data registers while Start is high will change internal values and may cause an error condition. The user must take care of the serial interface status before writing internal registers. In order to read the correct values on the data registers, the shift operation must be halted during the read accesses. Figure 18. Sample Basic Serial Port Connections Slave Mode Master Mode External EM 6521 SP[3]; SCLKOut Serial Clock In SP[3]; SCLKIn Serial Clock Out SP[2]; SOUT Serial Data In SP[2]; SOUT Serial Data In SP[0]; SIN Serial Data Out SP[0]; SIN Serial Data Out Ready Status Output SP[1]; Status Ready SP[1]: Status CS EM 6521 External optional connection Copyright © 2005, EM Microelectronic-Marin SA 25 www.emmicroelectronic.com R EM6521 6.7 Serial Interface Registers Table 6.7.1 Register RegSCntl1 Bit 3 2 1 Name MS1 MS0 POSnNeg Reset 0 0 0 R/W R/W R/W R/W Description Frequency selection Frequency selection Positive or negative clock edge selection for shift operation 0 MSBnLSB 0 R/W Shift MSB or LSB value first Default "0" is: Slave mode external clock, negative edge, LSB first Table 6.7.2 Frequency and Master Slave Mode Selection MS1 0 0 1 1 MS0 0 1 0 1 Description Slave mode: Clock from external Master mode: System clock / 4 Master mode: System clock / 2 Master mode: System clock Table 6.7.3 Register RegSCntl2 Bit Name Reset R/W Description 3 Start 0 R/W Enabling the interface, 2 Status 0 R/W Ready or Chip Select output on PSP[1] 1 OM[1] 0 R/W Output mode select 1 0 OM[0] 0 R/W Output mode select 0 Default "0" is: Interface disabled, status 0, serial mode, output tristate. Table 6.7.4 Register RegSDataL Bit Name 3 SerDataL[3] 2 SerDataL[2] 1 SerDataL[1] 0 SerDataL[0] Default "0" is: Data equal 0. Reset 0 0 0 0 R/W R/W R/W R/W R/W Description Serial data low nibble Serial data low nibble Serial data low nibble Serial data low nibble Reset 0 0 0 0 R/W R/W R/W R/W R/W Description Serial data high nibble Serial data high nibble Serial data high nibble Serial data high nibble Table 6.7.5 Register RegSDataH Bit Name 3 SerDataH[3] 2 SerDataH[2] 1 SerDataH[1] 0 SerDataH[0] Default "0" is: Data equal 0. Copyright © 2005, EM Microelectronic-Marin SA 26 www.emmicroelectronic.com R EM6521 Table 6.7.6 Register RegSPData Bit Name Reset R/W 3 SerPData[3] 0 R* /W 2 SerPData[2] 0 R* /W 1 SerPData[1] 0 R* /W 0 SerPData[0] 0 R* /W R* : The input terminal value is read, not the register Description Parallel output data Parallel output data Parallel output data Parallel output data Table 6.7.7 Option Register OPTNoPdPS Bit Name 3 NoPdPS[3] 2 NoPdPS[2] 1 NoPdPS[1] 0 NoPdPS[0] Default "0" is: Pull-down on 0 0 0 0 R/W R/W R/W R/W R/W Description No pull-down on PSP[3] No pull-down on PSP[2] No pull-down on PSP[1] No pull-down on PSP[0] R/W R/W R/W R/W R/W Description Nch. Open Drain on PSP[3] Nch. Open Drain on PSP[2] Nch. Open Drain on PSP[1] Nch. Open Drain on PSP[0] Table 6.7.8 Option Register OPTNchOpDPS Bit Name 3 NchOpDPS[3] 2 NchOpDPS[2] 1 NchOpDPS[1] 0 NchOpDPS[0] Default "0" is: CMOS output Copyright © 2005, EM Microelectronic-Marin SA 0 0 0 0 27 www.emmicroelectronic.com R EM6521 7 Melody, Buzzer A normal application is to drive a buzzer connected onto the terminal Buzzer. This peripheral cell is a combination of a 7 frequency tone generator and a 4-bit timer, used to provide a 50% duty cycle signal on the Buzzer terminal of a pre-selected length and frequency. The Buzzer terminal is active as long as the timer is not 0 or the SwBuzzer is set to ‘1’. The 4-bit timer can be used for another application independent of the Buzzer terminal by selecting "silence" instead of another frequency on the Buzzer output. "Silence" can also be used as part of a melody, or to switch off the buzzer. To use the buzzer independent of the 4-bit timer one has to set the switch SwBuzzer. This bit is in register RegMelTim and selects the signal duration on the buzzer output. If SwBuzzer=1 then the signal is output until the bit is set back to 0 . With SwBuzzer=0 the output signal duration is controlled by the 4bit timer. If neither the SwBuzzer or the timer are active, the Buzzer terminal is on 0. The high impedance state setting with BzOutEn is independent of the SwBuzzer and Timer settings. As soon as the bit is set to 1 the Buzzer terminal is set tristate. See also Figure 19. 12H Figure 19. Melody Generator Block Diagram BzO utEn Ck[16] (from Prescaler) 1 Frequency G enerator 0 M UX BZ Term inal V SS 8 FlBuzzer Frequency Select SwBuzzer Close Control Logic IR Q Bz Zero Auto 4 - Bit T im er T im er C lock (from Prescaler) Control & Status Registers Period Register Internal Data Bus DB[3:0] 7.1 4-Bit Timer The timer has 2 modes: - Single run mode (Auto=0) - Continuous run mode (Auto=1) Mode selection and timer count down frequency is done in register RegMelTim. All timer frequencies are coming from the prescaler. The 4-bit timer can be used independent of the melody buzzer application. Whenever the timer reaches 0 it generates an interrupt request IRQBz in the register RegIRQ2 . This interrupt can be masked with the bit MaskIRQBz in register RegIRQMask2. By writing 0 into the timer period register the timer stops immediately and does not generate an interrupt. Copyright © 2005, EM Microelectronic-Marin SA 28 www.emmicroelectronic.com R EM6521 7.1.1 Single Run Mode The timer duration is controlled by the RegMelPeri value and the selected timer frequency in RegMelTim. The timer is counting down from its previously charged value until it reaches 0. On 0 the timer stops and generates an interrupt request. The buzzer frequency output is enabled after the next positive timer clock edge and remains enabled until the timer reaches 0. Figure 20. Single Run Mode Tim er Clock Tim er Value 1 2 0 1 0 Buzzer IRQBz µP writes 1 into RegMelPeri µP writes 2 into RegMelPeri 7.1.2 Continuos Run Mode This is almost the same as the single run mode only that in this case the timer after reaching 0 reloads itself automatically with the register RegMelPeri value. Every time the timer reaches 0 an interrupt request is send. There are 2 ways to stop the continuos mode. • First, changing the mode to single run mode. As the timer reaches 0 it stops. The last period after Auto=0 is of length RegMelPeri + 1. • Second, loading 0 into the timer period register RegMelPeri stops the timer immediately, no interrupt is generated and the Auto flag is reset. The buzzer frequency output is enabled directly by writing Auto=1. Figure 21. Continuos Run Mode Timer Clock Timer Value 2 1 0 2 1 0 2 1 0 Buzzer IRQBz µP writes 2 into RegMelPeri n periods µP writes Auto = 1 Copyright © 2005, EM Microelectronic-Marin SA µP writes Auto = 0 n+1 periods 29 www.emmicroelectronic.com R EM6521 7.2 Programming Order Single run mode usage 1st, selecting the buzzer frequency into RegMelFSel. 2nd, selecting the timer clock frequency in RegMelTim. 3rd, selecting the timer period in RegMelPeri. --> On the next positive clock edge the buzzer output is enabled. Continuos run mode usage 1st, selecting the buzzer frequency into RegMelFSel. 2nd, selecting the timer clock frequency in RegMelTim (Auto=0). 3rd, selecting the timer period in RegMelPeri. 4th, set bit Auto in RegMelTim. --> Immediately the buzzer output is active. Avoid timer clock frequency switch during buzzer operation. 7.3 Melody Registers Table 7.3.1 Register RegMelFSel Bit Name Reset 3 BzOutEn 0 2 MelFSel[2] 0 1 MelFSel[1] 0 0 MelFSel[0] 0 Default : Buzzer tristate, silence R/W R/W R/W R/W R/W Description Buzzer Output tristate Buzzer frequency select Buzzer frequency select Buzzer frequency select Table 7.3.2 Buzzer Output Frequency Selection with MelFSel[2..0] MelFSel[2] 0 0 0 0 1 1 1 1 MelFSel[1] 0 0 1 1 0 0 1 1 MelFSel[0] 0 1 0 1 0 1 0 1 Frequency VSS (silence) SysClock/8 SysClock/10 SysClock/12 SysClock/14 SysClock/16 SysClock/20 SysClock/24 DO8 SOL7# FA7 RE7 DO7 SOL6# FA6 Table 7.3.3 Register RegMelTim Bit 3 Name Reset R/W Description SwBuzzer 0 W Write: switch buzzer FlBuzzer 0 R Read: flag buzzer 2 Auto 0 R/W Single or continuos run mode 1 FTimSel1 0 R/W Timer clock frequency select 0 FTimSel0 0 R/W Timer clock frequency select Default : Single run mode, Ck[3] from prescaler as timer clock Copyright © 2005, EM Microelectronic-Marin SA 30 www.emmicroelectronic.com R EM6521 Table 7.3.4 Timer Clock Frequency Select FTimSel0 FTimSel1 0 1 0 1 Timer Clock Ck[3] Ck[5] Ck[7] Ck[1] 0 0 1 1 On 32 KHz operation 4 Hz 16 Hz 64 Hz 1 Hz Table 7.3.5 Register RegMelPeri Bit 3 2 1 0 Name Per[3] Per[2] Per[1] Per[0] Reset 0 0 0 0 R/W W W W W Description Melody timer period MSB Melody timer period Melody timer period Melody timer period LSB The total timer period duration is calculated as following: Duration = Value(RegMelPeri) x 1/Ck[n] Where, Ck[n] is the timer clock frequency and Value(RegMelPeri) is the value of the register RegMelPeri. Copyright © 2005, EM Microelectronic-Marin SA 31 www.emmicroelectronic.com R EM6521 8 10-bit Counter The EM6521 has a built-in universal cyclic counter. It can be configured as 10, 8, 6 or 4-bit counter. If 10-bits are selected we call that full bit counting, if 8, 6 or 4-bits are selected we call that limited bit counting. The counter works in up- or down count mode. Eight clocks can be used as the input clock source, six of them are prescaler frequencies and two are coming from the input pads PA[0] and PA[3]. In this case the counter can be used as an event counter. The counter generates an interrupt request IRQCount0 every time it reaches 0 in down count mode or 3FF in up count mode. Another interrupt request IRQCntComp is generated in compare mode whenever the counter value matches the compare data register value. Each of this interrupt requests can be masked (default). See section 10 for more information about the interrupt handling. 12H A 10-bit data register CReg[9:0] is used to initialize the counter at a specific value (load into Count[9:0]). This data register (CReg[9:0]) is also used to compare its value against Count[9:0] for equivalence. A Pulse-Width-Modulation signal (PWM) can be generated and output on port B terminal PB[3]. Figure 22. 10-bit Counter Block Diagram PA[0] Ck[15] Ck[12] Ck[10] Ck[8] Ck[4] Ck[1] PA[3] En Comparator IRQCntComp ck PWM MUX ck Up/Down En Counter Read Register Load CountFSel2...0 IRQCount0 Up/Down Counter EvCount RegCCntl1, 2 RegCDataL, M, H (Count[9:0]) Up/Down Start EvCount Load RegCDataL, M, H (CReg[9:0]) Data Register EnComp DB[3:0] 8.1 Full and Limited Bit Counting Table 7.3.1. Counter length selection In Full Bit Counting mode the counter uses its maximum BitSel[1] BitSel[0 ] counter length of 10-bits length (default ). With the BitSel[1,0] bits in 0 0 10-Bit register RegCDataH one can lower the counter length, 0 1 8-Bit for IRQ generation, to 8, 6 or 4 bits. This means that actually the counter always uses all the 10-bits, but 1 0 6-Bit IRQCount0 generation is only performed on the number 1 1 4-Bit of selected bits. The unused counter bits may or may not be taken into account for the IRQComp generation depending on bit SelIntFull. Refer to chapter 8.4. 123H Copyright © 2005, EM Microelectronic-Marin SA 32 www.emmicroelectronic.com R EM6521 8.2 Frequency Select and Up/Down Counting 8 different input clocks can be selected to drive the Counter. The selection is done with bits CountFSel2…0 in register RegCCntl1. 6 of this input clocks are coming from the prescaler. The maximum prescaler clock frequency for the counter is half the system clock and the lowest is 1Hz. Therefore a complete counter roll over can take as much as 17.07 minutes (1Hz clock, 10 bit length) or as little as 977 μs (Ck[15], 4 bit length). The IRQCount0, generated at each roll over, can be used for time bases, measurements length definitions, input polling, wake up from Halt mode, etc. The IRQCount0 and IRQComp are generated with the system clock Ck[16] rising edge. IRQCount0 condition in up count mode is : reaching 3FF if 10-bit counter length (or FF, 3F, F in 8, 6, 4-bit counter length). In down count mode the condition is reaching ‘0’. The non-selected bits are ‘don’t care’. For IRQComp refer to section 8.4. 124H Note: The Prescaler and the Microprocessor clock’s are usually non-synchronous, therefore time bases generated are max. n, min. n-1 clock cycles long (n being the selected counter start value in count down mode). However the prescaler clock can be synchronized with µP commands using for instance the prescaler reset function. Figure 23. Counter Clock Timing P r e s c a le r F r e q u e n c ie s o r D e b o u n c e d P o r t A C lo c k s S y s te m C lo c k P r e s c a le r C lo c k C o u n tin g C o u n te r IR Q ’s N o n - D e b o u n c e d P o rt A C lo c k s ( S y s te m C lo c k In d e p e n d e n t) S y s te m C lo c k P o rt A C lo c k D iv id e d C lo c k C o u n tin g C o u n te r IR Q ’s The two remaining clock sources are coming from the PA[0] or PA[3] terminals. Refer to the Figure 10 on page 15 for details. Both sources can be either debounced (Ck[11] or Ck[8]) or direct inputs, the input polarity can also be chosen. The output after the debouncer polarity selector is named PA3 , PA0 respectively. For the debouncer and input polarity selection refer to chapter 6.3. In the case of port A input clock without debouncer, the counting clock frequency will be half the input clock on port A. The counter advances on every odd numbered port A negative edge ( divided clock is high level ). IRQCount0 and IRQComp will be generated on the rising PA3 or PA0 input clock edge. In this condition the EM6521 is able to count with a higher clock rate as the internal system clock (Hi-Frequency Input). Maximum port A input frequency is limited to 200kHz (@VDD ≥ 2.0 V). If higher frequencies are needed, please contact EM-Marin. In both, up or down count (default) mode, the counter is cyclic. The counting direction is chosen in register RegCCntl1 bit Up/Down (default ‘0’ is down count). The counter increases or decreases its value with each positive clock edge of the selected input clock source. Start up synchronization is necessary because one can not always know the clock status when enabling the counter. With EvCount=0, the counter will only start on the next positive clock edge after a previously latched negative edge, while the Start bit was already set to ‘1’. This synchronization is done differently if event count mode (bit EvCount) is chosen. Refer also to Figure 24. Internal Clock Synchronization. 125H 126H 127H 128H Copyright © 2005, EM Microelectronic-Marin SA 33 www.emmicroelectronic.com R EM6521 8.3 Event Counting The counter can be used in a special event count mode where a certain number of events (clocks) on the PA[0] or PA[3] input are counted. In this mode the counting will start directly on the next active clock edge on the selected port A input. The Event Count mode is switched on by setting bit EvCount in the register RegCCntl2 to ‘1’.PA[3] and PA[0] inputs can be inverted depending on register OPTIntEdgPA and should be debounced. The debouncer is switched on in register OPTDebIntPA bits NoDebIntPA[3,0]=0. Its frequency depends on the bit DebSel from register RegPresc setting. The inversion of the internal clock signal derived from PA[3] or PA[0] is active with IntEdgPA[3] respectively IntEdgPA[0] equal to 1. Refer also to Figure 10 for internal clock signal generation. 129H Figure 24. Internal Clock Synchronization Ck Ck Start Start Count[9:0] +/-1 EvCount = 0 8.4 +/-1 Count[9:0] Ck Ck Start Start Count[9:0] Count[9:0] EvCount = 0 EvCount = 1 +/-1 EvCount = 1 Compare Function A previously loaded register value (CReg[9:0]) can be compared against the actual counter value (Count[9:0]). If the two are matching (equality) then an interrupt (IRQComp) is generated. The compare function is switched on with the bit EnComp in the register RegCCntl2. With EnComp = 0 no IRQComp is generated. Starting the counter with the same value as the compare register is possible, no IRQ is generated on start. Full or Limited bit compare are possible, defined by bit SelIntFull in register RegSysCntl1. EnComp must be written after a load operation (Load = 1). Every load operation resets the bit EnComp. Full bit compare function. Bit SelIntFull is set to ‘1’. The function behaves as described above independent of the selected counter length. Limited bit counting together with full bit compare can be used to generate a certain amount of IRQCount0 interrupts until the counter generates the IRQComp interrupt. With PWMOn=‘1’ the counter would have automatically stopped after the IRQComp, with PWMOn=‘0’ it will continue until the software stops it. EnComp must be cleared before setting SelIntFull and before starting the counter again. Be careful, PWMOn also redefines the port B PB[3] output data.(refer to section 8.5). Limited bit compare With the bit SelIntFull set to ‘0’ (default) the compare function will only take as many bits into account as defined by the counter length selection BitSel[1:0] (see chapter 8.1). 130H 13H 8.5 Pulse Width Modulation (PWM) The PWM generator uses the behavior of the Compare function (see above) so EnComp must be set to activate the PWM function.. At each Roll Over or Compare Match the PWM state - which is output on port B PB[3] - will toggle. The start value on PB[3] is forced while EnComp is 0 the value is depending on the up or down count mode. Every counter value load operation resets the bit EnComp and therefore the PWM start value is reinstalled. Setting PWMOn to ‘1’ in register RegPresc routes the counter PWM output to port B terminal PB[3]. Insure that PB[3] is set to output mode . Refer to section 6.4 for the port B setup. The PWM signal generation is independent of the limited or full bit compare selection bit SelIntFull. However if SelIntFull = 1 (FULL) and the counter compare function is limited to lower than 10 bits one can generate a predefined number of output pulses. In this case, the number of output pulses is defined by the value of the unused counter bits. It will count from the start value until the IRQComp match. One must not use a compare value of hex 0 in up count mode nor a value of hex 3FF (or FF,3F, F if limited bit compare) in down count mode. 132H Copyright © 2005, EM Microelectronic-Marin SA 34 www.emmicroelectronic.com R EM6521 For instance, loading the counter in up count mode with hex 000 and the comparator with hex C52 which will be identified as : - bits[11:10] are limiting the counter to limits to 4 bits length, =03 - bits [9:4] are the unused counter bits = hex 05 (bin 000101), - bits [3:0] (comparator value = 2). (BitSel[1,0]) (number of PWM pulses) (length of PWM pulse) Thus after 5 PWM-pulses of 2 clocks cycles length the Counter generates an IRQComp and stops. The same example with SelIntFull=0 (limited bit compare) will produce an unlimited number of PWM at a length of 2 clock cycles. 8.5.1 How the PWM Generator works. For Up Count Mode; Setting the counter in up count and PWM mode the PB[3] PWM output is defined to be 0 (EnComp=0 forces the PWM output to 0 in upcount mode, 1 in downcount). Each Roll Over will set the output to ‘1’ and each Compare Match will set it back to ‘0’. The Compare Match for PWM always only works on the defined counter length. This, independent of the SelIntFull setting which is valid only for the IRQ generation. Refer also to the compare setup in chapter 8.4. 13H In above example the PWM starts counting up on hex 0, 2 cycles later compare match -> PWM to ‘0’, 14 cycles later roll over -> PWM to ‘1’ 2 cycles later compare match -> PWM to ‘0’ , etc. until the completion of the 5 pulses. The normal IRQ generation remains on during PWM output. If no IRQ’s are wanted, the corresponding masks need to be set. Figure 25. PWM Output in Up Count Mode Figure 26. PWM Output in Down Count Mode Clock Clock Count[9 :0] 03E 03F 000 001 ... Data-1 Data Roll-over Compare IRQCount0 Data+1 Data+2 Count[9 :0] 001 000 3FF 3FE ... Data+1 Data Data-1 Data-2 Roll-over Compare IRQCount0 IRQComp IRQComp PWM output PWM output In Down Count Mode everything is inverted. The PWM output starts with the ‘1’ value. Each Roll Over will set the output to ‘0’ and each Compare Match will set it back to ‘1’. For limited pulse generation one must load the complementary pulse number value. I.e. for 5 pulses counting on 4 bits load bits[9 :4] with hex 3A (bin 111010). 8.5.2 PWM Characteristics PWM resolution is : 10bits (1024 steps), 8bits (256 steps), 6bits (64 steps) or 4 bits (16 steps) the minimal signal period is : 16 (4-bit) x Fmax* -> 16 x 1/Ck[15] -> 977 µs (32 KHz) the maximum signal period is : 1024 x Fmin* -> 1024 x 1/Ck[1] -> 1024 s (32 KHz) the minimal pulse width is : 1 bit -> 1 x 1/Ck[15] -> 61 µs (32 KHz) * This values are for Fmax or Fmin derived from the internal system clock (32kHz). Much shorter (and longer) PWM pulses can be achieved by using the port A as frequency input. One must not use a compare value of hex 0 in up count mode nor a value of hex 3FF (or FF,3F, F if limited bit compare) in downcount mode. Copyright © 2005, EM Microelectronic-Marin SA 35 www.emmicroelectronic.com R EM6521 8.6 Counter Setup RegCDataL[3:0], RegCDataM[3:0], RegCDataH[1:0] are used to store the initial count value called CReg[9:0] which is written into the count register bits Count[9:0] when writing the bit Load to ‘1’ in RegCCntl2. This bit is automatically reset thereafter. The counter value Count[9:0] can be read out at any time, except when using non-debounced high frequency port A input clock. To maintain data integrity the lower nibble Count[3:0] must always be read first. The ShCount[9:4] values are shadow registers to the counter. To keep the data integrity during a counter read operation (3 reads), the counter values [9:4] are copied into these registers with the read of the count[3:0] register. If using non-debounced high frequency port A input the counter must be stopped while reading the Count[3:0] value to maintain the data integrity. In down count mode an interrupt request IRQCount0 is generated when the counter reaches 0. In up count mode, an interrupt request is generated when the counter reaches 3FF (or FF,3F,F if limited bit counting). Never an interrupt request is generated by loading a value into the counter register. When the counter is programmed from up into down mode or vice versa, the counter value Count[9:0] gets inverted. As a consequence, the initial value of the counter must be programmed after the Up/Down selection. Loading the counter with hex 000 is equivalent to writing stop mode, the Start bit is reset, no interrupt request is generated. How to use the counter; If PWM output is required one has to put the port B[3] in output mode and set PWMOn=1 in step 5. 1st, set the counter into stop mode (Start=0). 2nd, select the frequency and up- or down count mode in RegCCntl1. 3rd, write the data registers RegCDataL, RegCDataM, RegCDataH (counter start value and length) 4th, load the counter, Load=1, and choose the mode. (EvCount, EnComp=0) 5th, select bits PWMOn in RegPresc and SelIntFull in RegSysCntl1 6th, if compare mode desired , then write RegCDataL, RegCDataM, RegCDataH (compare value) 7th, set bit Start and select EnComp in RegCCntl2 8.7 10-bit Counter Registers Table 8.7.1 Register RegCCntl1 Bit Name Reset R/W 3 Up/Down 0 R/W 2 CountFSel2 0 R/W 1 CountFSel1 0 R/W 0 CountFsel0 0 R/W Default : PA0 ,selected as input clock, Down counting Description Up or down counting Input clock selection Input clock selection Input clock selection Table 8.7.2 Counter Input Frequency Selection with CountFSel[2..0] CountFSel2 0 0 0 0 1 1 1 1 CountFSel1 0 0 1 1 0 0 1 1 Copyright © 2005, EM Microelectronic-Marin SA CountFSel0 0 1 0 1 0 1 0 1 36 clock source selection Port A PA[0] Prescaler Ck[15] Prescaler Ck[12] Prescaler Ck[10] Prescaler Ck[8] Prescaler Ck[4] Prescaler Ck[1] Port A PA[3] www.emmicroelectronic.com R EM6521 Table 8.7.3 Register RegCCntl2 Bit Name Reset R/W Description 3 Start 0 R/W Start/Stop control 2 EvCount 0 R/W Event counter enable 1 EnComp 0 R/W Enable comparator 0 Load 0 R/W Write: load counter register; Read: always 0 Default : Stop, no event count, no comparator, no load Table 8.7.4 Register RegSysCntl1 Bit Name Reset 3 IntEn 0 2 SLEEP 0 1 SelIntFull 0 0 ChTmDis 0 Default : Interrupt on limited bit compare R/W R/W R/W R/W R/W Description General interrupt enable Sleep mode Compare Interrupt select For EM test only Table 8.7.5 Register RegCDataL, Counter/Compare Low Data Nibble Bit Name Reset R/W 3 CReg[3] 0 W 2 CReg[2] 0 W 1 CReg[1] 0 W 0 CReg[0] 0 W 3 Count[3] 0 R 2 Count[2] 0 R 1 Count[1] 0 R 0 Count[0] 0 R Description Counter data bit 3 Counter data bit 2 Counter data bit 1 Counter data bit 0 Data register bit 3 Data register bit 2 Data register bit 1 Data register bit 0 Table 8.7.6 Register RegCDataM, Counter/Compare Middle Data Nibble Bit Name Reset R/W 3 CReg[7] 0 W 2 CReg[6] 0 W 1 CReg[5] 0 W 0 CReg[4] 0 W 3 ShCount[7] 0 R 2 ShCount[6] 0 R 1 ShCount[5] 0 R 0 ShCount[4] 0 R Description Counter data bit 7 Counter data bit 6 Counter data bit 5 Counter data bit 4 Data register bit 7 Data register bit 6 Data register bit 5 Data register bit 4 Table 8.7.7 Register RegCDataH, Counter/Compare High Data Nibble Bit Name Reset R/W Description 3 BitSel[1] 0 R/W Bit select for limited bit count/compare 2 BitSel[0] 0 R/W Bit select for limited bit count/compare 1 CReg[9] 0 W Counter data bit 9 0 CReg[8] 0 W Counter data bit 8 1 ShCount[9] 0 R Data register bit 9 0 ShCount[8] 0 R Data register bit 8 Table 8.7.8 Counter Length Selection BitSel[1] BitSel[0 ] counter length 0 0 10-Bit 0 1 8-Bit 1 0 6-Bit 1 1 4-Bit Copyright © 2005, EM Microelectronic-Marin SA 37 www.emmicroelectronic.com R EM6521 9 Millisecond Counter The EM6521 has a built-in millisecond binary coded decimal counter. It can be used to measure the time elapsed between two events (hardware or software events). With a system clock of 32kHz, the counter generates every 1/10 second or every second an interrupt request. The counter value read on registers RegMSCDataL, RegMSCDataM and RegMSCDataH is in binary coded decimal format (000 to 999). To maintain the data integrity for the 3 decimal digits inside BCD[11:0] one must stop the counter while reading the full 3 digit value. An overflow flag FlSec is set whenever the counter reached 999. This flag is helpful when the counter is used in polling mode and twice the same value is read. In this case, if the flag is set to 1, it indicates that the two readings were 1 second apart, in the case the flag is not set, the two readings must have been very short one after the other. After every read of RegMSCCntl2 the FlSec gets automatically reset. The millisecond counter is reset with every system reset. Setting the ResMSC flag located in register RegMSCCntl1 resets the counter value only. This flag is automatically reset after the write operation. For good resolution in Pa3-mode use the Ck[14 ] debouncer clock (250us). Or if the 1/1000 sec is not relevant then choose Ck[10] (4ms) as debouncer clock. Doing so will save power. The debouncer selection is made in register RegMSCCntl2 bit DebFreqSel. Figure 27. MSC Block Diagram This signal used as reference in text description PA[3] Term inal Ck[14 Ck[10] RegMSCCntl1,2 PosEdg PA3 Debouncer 0 NegEdg 1 1 PA3Internal 0 Start/Stop Control dT/MSC Data Data BCD 1/10 Sec BCD 1/100 Sec 1/10 Sec PA3/uP 4 Data Bus FlSecl dT/MSC EN PA3Edge DebFreqSel RunEn Data BCD 1/1000 Sec CK1000 0 1 Sec IRQMSC 1 IntSel Changing PA3Edge while RunEn=1 or PA3/up=1 may generate a MSC event (start or stop). This behavior is useful for the - CPU controlled start and PA3 controlled stop - mode, But in general one does all the setup before starting the counter. 9.1 PA[3] Input for MSC In hardware Start/Stop mode the counter is triggered with the port A terminal PA[3] input. In this case PA[3] is debounced with the prescaler Ck[14] (or Ck[10]) clock. The triggering edge selection is made with bit PA3Edge in register RegMSCCntl2 (default negative edge). The PA[3] input for the millisecond counter is totally independent of the PA[3] interrupt edge selection and the PA[3] polarity selection for the 10 bit counter. However the pull-up or pull-down selection is common to all peripheries sharing the port A. 9.2 IRQ from MSC An Interrupt request IRQMSC is send on either every 1/10 seconds or every second, depending on the bit IntSel in register RegMSCCntl2. For interrupt handling please refer to the interrupt control section. Copyright © 2005, EM Microelectronic-Marin SA 38 www.emmicroelectronic.com R EM6521 9.3 MSC-Modes The millisecond counter can have many different modes of operation. The most common are : - CPU controlled start and stop. - CPU controlled start and PA[3] controlled stop. - Port A terminal PA[3] controlled start and stop mode. - Pulse width measurement of port A terminal PA[3] input signals. All these different modes are controlled with the bits in the registers RegMSCCntl1 and RegMSCCntl2. The main bits are : - dT/MSC ; Pulse-width or start stop measure. This bit only has a action if PA[3] input is chosen. If pulsewidth measure is selected, the counter starts with the first active edge on PA[3] and stops with the next inverse edge (sets RunEn = 0). If MSC measure selected, the counter starts with the first active PA[3] edge, stops on the next, restarts on the following etc. It does not reset RunEn. - PA3/µP ; Direct port A terminal PA[3] or CPU (µP) controlled start and stop function. If direct PA[3] controlled start stop mode is chosen the counter, once enabled by setting RunEn/Stop = 1, starts counting on the first active edge seen on PA[3]. It stops counting depending on the dT/MSC bit either on the next inverse edge or on the next active edge. If µP is chosen, the counter starts and stops depending on bit RunEn/Stop. - RunEn/Stop; In CPU mode this bit starts or stops the counter. In PA3 mode it enables the counter which will start with the next event on port A terminal PA[3]. If dT and PA3 mode, the RunEn gets reset with the second active PA[3] edge. - PA3Edge ; 9.4 This bit selects the active PA[3] edge which will trigger the dT/MSC selected measurement mode. It has no effect if PA3/µP=0. Default 0 is negative edge. Mode selection Before using, the MSC counter needs to be reset by setting bit ResMSC to ‘1’. This bit is automatically reset thereafter. Then select the IRQ frequency and the counting mode. Now the RunEn can be set to ‘1’ . To display the counter value during run you may only want to read the MSB (1/10 sec) digit ,driven by IRQ or with polling, and fully read the MSC value only once the counter is stopped. The counter data registers are read only. Any Reset (system reset, POR, watchdog) is setting the MSC into stop mode and clears the counter registers. • CPU controlled Start and Stop As soon as the CPU writes the start bit RunEn/Stop=1 the counter starts up counting until the CPU clears the start bit. The bit PA3/uP is ‘0’ for this mode. Figure 28. CPU controlled Start Stop CPU write RunEn/Stop Start Counter Copyright © 2005, EM Microelectronic-Marin SA Stop Counting 39 www.emmicroelectronic.com R EM6521 • CPU controlled Start and PA[3] controlled Stop. In this mode setting the bit RunEn=1 while PA3/uP=0 while immediately start the counting action. Afterwards one needs to prepare for the stop by PA[3]. Therefore the PA[3] start condition must first be fulfilled. This is in dT mode a rising edge on the PA3internal signal (PA3internal, refer to Figure 27). In MSC mode the start condition is a positive pulse on PA3internal signal. The creation of this edge or pulse is done per software by manipulating the PA3Edge selection. See Figure 29 for details. Afterwards one can change to PA3 controlled stop mode (PA3/uP=1) where the next positive edge on PA3internal will stop the Counter. In dT mode the RunEn/stop bit will be cleared with the PA3 stop condition where as in MSC mode MSC mode the RunEn is not cleared. 134H 135H Figure 29. CPU controlled Start PA[3] controlled Stop d T / M S C = 1 , S t o p o n P A [ 3 ] R is in g E d g e d T / M S C = 1 , S t o p o n P A [ 3 ] F a llin g E d g e C P U W r ite C P U W r ite R u n E n /S to p R u n E n /S to p P A 3 /u P P A 3 /u P P A [3 ] P A [3 ] PA3Edge PA3Edge P A 3 In te rn a l P A 3 In te rn a l C o u n t in g C ount S ta rt µP S ta rt PA3 S to p Set I n it ia l V a lu e s S ta rt µP d T / M S C = 0 , S t o p o n P A [ 3 ] R is in g E d g e C P U W r ite R u n E n /S to p R u n E n /S to p P A 3 /u P P A 3 /u P P A [3 ] P A [3 ] PA3Edge PA3Edge P A 3 In te rn a l P A 3 In te rn a l C o u n t in g S ta rt µP S ta rt PA3 S ta rt PA3 Set I n it ia l V a lu e s S ta rt µP • Pulse-width measurement of PA[3] Input Signals. In this mode the bit dT/MSC=1 and PA3/uP=1. Setting RunEn/stop=1 enables the operation. The first positive edge on PA3Internal signal will start the counter, the following negative edge will stop the counter end set bit RunEn/Stop to 0 . PA3internal signal is a copy of the PA[3] terminal status if PA3Edge=1. with PA3Edge=0 PA3Internal has the inverted PA[3] value. See also Figure 27 and Figure 30. 137H • Port A PA[3] controlled Start and Stop Mode. In this mode the bit dT/MSC=0 and PA3/uP=1. Setting RunEn/stop=1 enables the operation. The first positive edge on PA3Internal signal will start the counter , the second edge will stop the counter, the third one will restart, etc, . PA3internal signal is a copy of the PA[3] terminal status if PA3Edge=1. With PA3Edge=0 PA3Internal has the inverted PA[3] value. See also Figure 27 and Figure 30. 138H Copyright © 2005, EM Microelectronic-Marin SA Set I n it ia l V a lu e s C o u n t in g C ount S to p S to p d T / M S C = 0 , S t o p o n P A [ 3 ] F a llin g E d g e C P U W r ite C ount 136H C o u n t in g C ount 139H 40 S ta rt PA3 S to p Set I n it ia l V a lu e s Figure 30. dT/MSC behavior dT/MSC, PA3/up=1 Pulse-width Measurem ent PA3 internal start stop Counting Counter RunEn dT/MSC=0, PA3/up=1 Period m easurem ent PA3 internal start Counter RunEn stop Counting restart Counting www.emmicroelectronic.com R EM6521 9.5 Millisecond Counter Registers Table 9.5.1 Register RegMSCCntl1 Bit 3 2 1 0 Name RunEn/Stop PA3/µP dT/MSC ResMSC Reset 0 0 0 0 R/W R/W R/W R/W R/W Description Enable counter Port A or CPU start stop control Pulse-width measurement Reset if write of 1 Read value is always 0 Default: Stop, CPU controlled. Table 9.5.2 Register RegMSCCntl2 Bit Name Reset R/W Description 3 DebFreqSel 0 R/W Debouncer frequency select 2 PA3Edge 0 R/W PA[3] edge selection 1 IntSel 0 R/W Interrupt source selection 0 FlSec 0 R Seconds flag Default: Ck[14] is debouncer clock, negative edge, 1/10 Sec Interrupt requests Table 9.5.3 Register RegMSCDataL Bit 3 2 1 0 Name BCD[3] BCD[2] BCD[1] BCD[0] Reset 0 0 0 0 R/W R R R R Description 1/1000 Seconds BCD value 3 1/1000 Seconds BCD value 2 1/1000 Seconds BCD value 1 1/1000 Seconds BCD value 0 Reset 0 0 0 0 R/W R R R R Description 1/100 Seconds BCD value 3 1/100 Seconds BCD value 2 1/100 Seconds BCD value 1 1/100 Seconds BCD value 0 Reset 0 0 0 0 R/W R R R R Description 1/10 Seconds BCD value 3 1/10 Seconds BCD value 2 1/10 Seconds BCD value 1 1/10 Seconds BCD value 0 Table 9.5.4 Register RegMSCDataM Bit 3 2 1 0 Name BCD[7] BCD[6] BCD[5] BCD[4] Table 9.5.5 Register RegMSCDataH Bit 3 2 1 0 Name BCD[11] BCD[10] BCD[9] BCD[8] Copyright © 2005, EM Microelectronic-Marin SA 41 www.emmicroelectronic.com R EM6521 10 Interrupt Controller The EM6521 has 12 different interrupt request sources, each of which is maskable. Five of them come from external sources and seven from internal sources. External(4) - Port A, - Serial Interface PA[3] .. PA[0] inputs Internal(8) - Prescaler - Melody timer - Serial Interface - Millisecond-Counter - 10-bit Counter Ck[1], Blink, 32Hz/8Hz 1/10Sec or 1Sec Count0, CountComp To be able to send an interrupt to the CPU, at least one of the interrupt request flags must ‘1’ (IRQxx) and the general interrupt enable bit IntEn located in the register RegSysCntl1 must be set to 1. The interrupt request flags can only be set high by a positive edge on the IRQxx data flip-flop while the corresponding mask register bit (MaskIRQxx) is set to 1. Figure 31. Interrupt Controller Block Diagram One of these Blocks for each IRQ DB DB[n] Mask Interrupt Request Capture Register General INT En Write Write IRQ to µP IRQxx 12 Input-OR Read ClrIntBit Reset At power on or after any reset all interrupt request mask registers are cleared and therefore do not allow any interrupt request to be stored. Also the general interrupt enable IntEn is set to 0 (No IRQ to CPU) by reset. After each read operation on the interrupt request registers RegIRQ1, RegIRQ2 or RegIRQ3 the contents of the addressed register are reset. Therefore one has to make a copy of the interrupt request register if there was more than one interrupt to treat. Each interrupt request flag may also be reset individually by writing 1 into it . Interrupt handling priority must be resolved through software by deciding which register and which flag inside the register need to be serviced first. Since the CPU has only one interrupt subroutine and the IRQxx registers are cleared after reading, the CPU does not miss any interrupt request which comes during the interrupt service routine. If any occurs during this time a new interrupt will be generated as soon as the software comes out of the current interrupt subroutine. Copyright © 2005, EM Microelectronic-Marin SA 42 www.emmicroelectronic.com R EM6521 Any interrupt request sent by a periphery cell while the corresponding mask is not set will not be stored in the interrupt request register. All interrupt requests are stored in their IRQxx registers depending only on their mask setting and not on the general interrupt enable status. Whenever the EM6521 goes into halt mode the IntEn bit is automatically set to 1, thus allowing to resume from halt mode with an interrupt. 10.1 Interrupt Control Registers Table 10.1.6 Register RegIRQ1 Bit Name Reset R/W 3 IRQPA[3] 0 R* 2 IRQPA[2] 0 R* 1 IRQPA[1] 0 R* 0 IRQPA[0] 0 R* *; Writing of 1 clears the corresponding bit. Description Port A PA[3] interrupt request Port A PA[2] interrupt request Port A PA[1] interrupt request Port A PA[0] interrupt request Table 10.1.7 Register RegIRQ2 Bit Name Reset R/W 3 IRQHz1 0 R* 2 IRQHz32/8 0 R* 1 IRQBlink 0 R* 0 IRQBz 0 R* *; Writing of 1 clears the corresponding bit. Description Prescaler interrupt request Prescaler interrupt request Prescaler interrupt request Melody timer interrupt request Table 10.1.8 Register RegIRQ3 Bit Name Reset R/W 3 IRQSerial 0 R* 2 IRQMSC 0 R* 1 IRQCount0 0 R* 0 IRQCntComp 0 R* *; Writing of 1 clears the corresponding bit. Description Serial interrupt request Millisecond counter int. request Counter interrupt request Counter interrupt request Table 10.1.9 Register RegIRQMask1 Bit 3 2 1 0 Name Reset MaskIRQPA[3] 0 MaskIRQPA[2] 0 MaskIRQPA[1] 0 MaskIRQPA[0] 0 Interrupt is not stored if the mask bit is 0. R/W R/W R/W R/W R/W Description Port A PA[3] interrupt mask Port A PA[2] interrupt mask Port A PA[1] interrupt mask Port A PA[0] interrupt mask R/W R/W R/W R/W R/W Description Prescaler interrupt mask Prescaler interrupt mask Prescaler interrupt mask Melody timer interrupt mask R/W R/W R/W R/W R/W Description Serial interrupt mask Millisecond counter int. mask Counter interrupt mask Counter interrupt mask Table 10.1.10 Register RegIRQMask2 Bit 3 2 1 0 Name Reset MaskIRQHz1 0 MaskIRQHz32/8 0 MaskIRQBlink 0 MaskIRQBz 0 Interrupt is not stored if the mask bit is 0. Table 10.1.11 Register RegIRQMask3 Bit 3 2 1 0 Name Reset MaskIRQSerial 0 MaskIRQMSC 0 MaskIRQCount0 0 MaskIRQCntComp 0 Interrupt is not stored if the mask bit is 0 Copyright © 2005, EM Microelectronic-Marin SA 43 www.emmicroelectronic.com R EM6521 11 Supply Voltage Level Detector The EM6521 has a built-in Supply Voltage Level Detector (SVLD) circuitry, such that the CPU can compare the supply voltage against a pre-selected value. During sleep mode this function is inhibited. The CPU activates the supply voltage level detector by writing VldStart = 1 in the register Figure 32. SVLD Timing Diagram RegVldCntl. The actual measurement starts on SVLD > VBAT SVLD < VBAT the next Ck[9] rising edge and lasts during the VBAT =VDD Ck[9] high period (2 ms at 32 KHz). The busy Compare Level flag VldBusy stays high from VldStart set until the measurement is finished. The worst case Ck[9] (256 Hz) time until the result is available is 1.5 Ck[9] CPU starts CPU starts prescaler clock periods (32 KHz -> 6 ms). The measure measure detection level must be defined in register Busy Flag RegVldLevel before the VldStart bit is set. During the actual measurement (2 ms) the Measure device will draw an additional 5 µA of IVDD 0 1 current. After the end of the measure the result Result is available by inspection of the bit VldResult. Read Result If the result is read 0, then the power supply voltage was greater than the detection level value. If read 1, the power supply voltage was lower than the detection level value. During each read while Busy=1 the VldResult is not guaranteed. For compatibility reasons the SVLD levels available on the EM6521 are kept the same as the levels used on the EM6621. This means that all levels which may be lower2.0V could not be reached anymore because they are below VDD min. 11.1 SVLD Register Table 11.1.1 Register RegVldCntl Bit Name Reset R/W 3 VldResult 0 R* 2 VldStart 0 W 2 VldBusy 0 R 1 NoOscWD 0 R/W 0 NoLogicWD 0 R/W R*; Read value while VLDBusy=1 is not guaranteed. Table 11.1.2 Register RegVldLevel (Detection Level Value) Bit 3 2 1 0 Name -VldLevel2 VldLevel1 VldLevel0 Reset x 0 0 0 R/W -R/W R/W R/W Description Vld result flag Vld start Vld busy flag No Oscillator watchdog No logic watchdog Description not active Vld level selection Vld level selection Vld level selection Table 11.1.3 Voltage Level Detector Value Selecting VldLevel2 VldLevel1 VldLevel0 Typical voltage level Level1 0 0 0 4.00 Level2 0 0 1 2.95 Level3 0 1 0 2.35 Level4 0 1 1 1.95*1 Level5 1 0 0 1.70**2 Level6 1 0 1 1.45**2 Level7 1 1 0 1.30**2 Level8 1 1 1 1,20**2 *1 level which may not be reached anymore because it can be lower than VDD min. **2 levels which are too far below VDD min to be reached. (Are here for software compatibility with EM6621). Copyright © 2005, EM Microelectronic-Marin SA 44 www.emmicroelectronic.com R EM6521 12 Strobe Output The Strobe output is used to indicate either the EM6521 reset condition, a write operation on port B (WritePB) or the sleep mode. The selection is done in register RegLcdCntl1. Per default, the reset condition is output on the Strobe terminal. For a port B write operation the strobe signal goes high for half a system clock period. Data can be latched on the falling edge of the strobe signal. This function is used to indicate when data on port B output terminals is changing. The reset signal on the Strobe output is a copy of the internal CPU reset signal. The Strobe pin remains active high as long as the CPU gets the reset. Both the reset condition and the port B write operation can be output simultaneously on the Strobe pin. The strobe output select latches are reset by initial power on reset only. Figure 33 . Strobe Output Table 11.1.1. Strobe Output Selection StrobeOutSel1 StrobeOutSel0 0 0 0 1 1 1 0 1 Strobe Terminal Output System Reset System Reset and WritePB WritePB Sleep Reset 0 Reset, WritePB 1 WritePB 2 Sleep 3 Terminal Strobe 0 1 StrobeOutSel0 StrobeOutSel1 12.1 Strobe Register Table 12.1.1 Register RegLCDCntl1 Bit Name 3 2 1 0 StrobeOutSel1 StrobeOutSel0 CkTripSel1 CkTripSel0 power on value 0 0 0 0 R/W Description R/W R/W R/W R/W Strobe output select Strobe output select LCD multiplier clock select LCD multiplier clock select The CKTripSel1, CKTripSel0 values are reset with every system reset. Copyright © 2005, EM Microelectronic-Marin SA 45 www.emmicroelectronic.com R EM6521 13 RAM The EM6521 has two 64x4 bit RAM’s built-in. The main RAM (RAM1) is direct addressable on addresses decimal(0 to 63). A second RAM (RAM2) is indirect addressable on addresses 64,65, 66 and 67 together with the index from RegIndexAdr. Figure 34. Ram Architecture 64 x 4 direct addressable RAM1 RAM1_63 RAM1_61 4 bit R/W 4 bit R/W 4 bit R/W RAM1_60 4 bit R/W RAM1_62 64 x 4 indexed addressable RAM2 RAM2_3 RAM2_2 . . . RAM1_3 RAM1_2 RAM1_1 RAM1_0 . . . 4 bit R/W 4 bit R/W 4 bit R/W 4 bit R/W RAM2_1 RAM2_0 RegIndexAdr[F] RegIndexAdr[E] ... RegIndexAdr[1] RegIndexAdr[0] RegIndexAdr[F] RegIndexAdr[E] ... RegIndexAdr[1] RegIndexAdr[0] 4 bit R/W 4 bit R/W ... 4 bit R/W 4 bit R/W 4 bit R/W 4 bit R/W ... 4 bit R/W 4 bit R/W RegIndexAdr[F] RegIndexAdr[E] ... RegIndexAdr[1] RegIndexAdr[0] 4 bit R/W 4 bit R/W ... 4 bit R/W 4 bit R/W RegIndexAdr[F] RegIndexAdr[E] ... 4 bit R/W 4 bit R/W ... 4 bit R/W 4 bit R/W RegIndexAdr[1] RegIndexAdr[0] The RAM2 addressing is indirect using the RegIndexAdr value as an offset to the directly addressed base RAM2_0, RAM2_1 , RAM2_2 or RAM2_3 registers. To write or read the RAM2 the user has first to set the offset value in the RegIndexAdr register. The actual access then is made on the RAM2 base addresses RAM2_0 , RAM2_1, RAM2_2 or RAM2_3. Refer to Figure 34. Ram Architecture, for the address mapping. 140H i.e. Writing hex(5) to Ram2 add location 30: First write hex(E) to RegIndexAdr, then write hex(5) to RAM2_1 RAM Extension : Unused R/W Registers can often be used as possible RAM extension. Be careful not to use register which start, stop, or reset some functions. Unused LCD register latches can also be used as RAM memory. In case of 3 times multiplex and using all the 20 Segment outputs you may have five additional 4 bit registers.. Also for each unused Segment output you may have one additional 4 bit register. Copyright © 2005, EM Microelectronic-Marin SA 46 www.emmicroelectronic.com R EM6521 14 LCD Driver The EM6521 has a built-in Liquid Crystal Display (LCD) driver. A maximum of 80 Segments can be displayed using the 20 Segment driver outputs (SEG[20:1) in 4:1 multiplex ,60 Segments in the case of 3:1 multiplex, and the 4 back-planes (COM[4:1]). The LCD driver has its own voltage regulator (1.05 Volt) and voltage multiplier to generate the driver bias voltages VL1, VL2 and VL3 (VLCD). Using the metal1 mask (ROM version only) the user can choose higher LCD reference voltages. Please check with EM Marin the possible values and their impact on power consumption. The special architecture of this LCD driver allows the user to freely specify the data and address for each individual Segment using the interconnect metal2 mask (ROM version only) . It therefore adapts to every possible LCD display with a maximum of 80 independent segments. The LCD clock frequency is 256Hz. Thus the frame frequency is 256/8 Hz if 4:1 multiplex, or 256/6 if 3:1 multiplex. Figure 35. LCD Architecture VL3 x3 LCD Off Enable VL2 x2 RefLCD LCD External Supply Voltage Multiplier VL1 x1 LCD Blank 1 Von Phase 1 to 4 Voff 2 MUX SEG[n] 3 4 Address Bus Data Bus Phase Selection Data Latches Copyright © 2005, EM Microelectronic-Marin SA 47 Output Switches www.emmicroelectronic.com R EM6521 14.1 LCD Control The LCD driver has two control registers RegLCDCntl1, RegLCDCntl2 to optimize for display contrast, power consumption, operation mode and bias voltage source. LCDExtSupply: Choosing external supply (LCDExtSupply =‘1’) disables the internal LCD voltage regulator and voltage multiplier, it also puts the bias voltage terminals VL1, VL2 and VL3 into high impedance state. External bias levels can now be connected to VL1, VL2 and VL3 terminals. (Resistor divider chain or others). Another way to adapt the VL1, VL2 and VL3 levels to specific user needs is to overdrive the VL1 output (LCDExtSupply =0) with the desired value. The internal multiplier will multiply this new VL1 level to generate the corresponding levels VL2 and VL3. The bit LCDExtSupply is only reset by initial POR. LCD4Mux: With this switch one selects either 3:1 or 4:1 (default) times multiplexing of the 20 Segment driver outputs. In the case of 3:1 multiplexing the COM[4] is off. LCDOff: Disables the LCD. The voltage multiplier and regulator are switched off ( 0 current ).The Segment latch information is maintained. The VL1,VL2 and VL3 outputs are pulled to VSS. LCDBlank: All Segment outputs are turned off. The voltage multiplier and regulator remain switched on. LCDBlank can be used with the 1Hz and Blink interrupt to let the whole display blink (software controlled). CkTripSel1,0: Selecting the appropriate voltage multiplier frequency to optimize display contrast and power consumption. The value to use is also depending on the selected multiplier booster capacitors (typically 100nF). 14.2 LCD Addressing The LCD driver addressing is indirect using the RegIndexAdr value as an offset to the directly addressed base LCD_1, LCD_2 or LCD_3 registers. All LCD Segment registers are R/W. At address LCD_3 only the first 8 Index locations are usable. The Index locations hex(8 to F) are non implemented. A total of 40 addresses are available to the user to freely define the addressing of the LCD Segment latches. For each of these latches the user may choose the address and data to be connected. See also section 14.3. However only 20x4 LCD Segment latches are implemented. The unused address locations are empty and can not be used as RAM. Figure 36. LCD Address Mapping 40 x 4 Indexed Addressable LCD Latches but Maximum 20x4 Bits are R/W RegIndexAdr[8] RegIndexAdr[7] ... LCD_3 RegIndexAdr[1] RegIndexAdr[0] RegIndexAdr[F] RegIndexAdr[E] ... LCD_2 RegIndexAdr[1] 14H ... RegIndexAdr[F] RegIndexAdr[E] 4 bit R/W 4 bit R/W RegIndexAdr[1] 48 4 bit R/W 4 bit R/W RegIndexAdr[0] RegIndexAdr[0] Copyright © 2005, EM Microelectronic-Marin SA ... 4 bit R/W 4 bit R/W 4 bit R/W 4 bit R/W ... LCD_1 4 bit R/W 4 bit R/W ... 4 bit R/W 4 bit R/W www.emmicroelectronic.com R EM6521 14.3 Free Segment Allocation Each Segment (SEG[20:1]) terminal outputs the time multiplexed information from its 4 Segment data latches. Information stored in latch 1 is output during phase1, latch 2 during phase 2, latch 3 during phase 3 and latch 4 during phase 4. In the case of 3 to 1 multiplexing the phase 4 and the latch 4 are not used. This phase information on the segment outputs together with the common outputs (COM[4:1]) - also called back-planes defines if a given LCD segment is light or not. COM[1] is on during phase 1 and off during phase 2,3,4 , COM[2] is on during phase 2 and off during phase 1,3,4 , etc. For each segment data latch the address location within the LCD address spacing (LCD_3 + Index(8), LCD_2 + Index(16), LCD_1 + Index(16) --> LCDAdr[39:0]) can be user defined. For each segment data latch the data bus connection (DB[3:0]) can be user defined. Table 14.3.1 Default LCD Configuration used on EM6521 Segment outputs COM[1] = phase1 COM[2] = phase2 COM[3] = phase3 COM[4] = phase4 SEG[1] DB[0], LCDAdr[0] DB[1], LCDAdr[0] DB[2], LCDAdr[0] DB[3], LCDAdr[0] SEG[2] DB[0], LCDAdr[1] DB[1], LCDAdr[1] DB[2], LCDAdr[1] DB[3], LCDAdr[1] SEG[3] DB[0], LCDAdr[2] DB[1], LCDAdr[2] DB[2], LCDAdr[2] DB[3], LCDAdr[2] ... ... ... ... ... SEG[18] DB[0], LCDAdr[18] DB[1], LCDAdr[18] DB[2], LCDAdr[18] DB[3], LCDAdr[18] SEG[19] DB[0], LCDAdr[19] DB[1], LCDAdr[19] DB[2], LCDAdr[19] DB[3], LCDAdr[19] SEG[20] DB[0], LCDAdr[20] DB[1], LCDAdr[20] DB[2], LCDAdr[20] DB[3], LCDAdr[20] 14.4 LCD Registers Table 14.4.1 Register RegLcdCntl1 Bit Name Reset R/W 3 StrobeOutSel1 POR to ‘0’ R/W 2 StrobeOutSel0 POR to ‘0’ R/W 1 CkTripSel1 0 R/W 0 CkTripSel0 0 R/W StrobeOutSel1,0 is reset by initial power on only. Description Strobe output select Strobe output select LCD multiplier clock select LCD multiplier clock select Table 14.4.2 Multiplier Clock Frequency Select CkTripSel0 0 1 0 1 CkTripSel1 0 0 1 1 Multiplier Clock Ck[10] Ck[9] Ck[8] Ck[7] on 32 KHz operation 512 Hz 256 Hz 128 Hz 64 Hz Table 14.4.3 Register LcdCntl2 Bit Name Reset 3 LCDBlank 1 2 LCDOff 1 1 LCD4Mux 1 POR to ‘0’ 0 LCDExtSupply LCDExtSupply is reset to ‘0’ by POR only. Copyright © 2005, EM Microelectronic-Marin SA R/W R/W R/W R/W R/W Description LCD Segment outputs off LCD off (multiplier off) 4 : 1 multiplexed External supply for VL1, VL2 and VL3 49 www.emmicroelectronic.com R EM6521 Figure 37 LCD Multiplexing Waveform SEG[1] SEG[2] SEG[3] SEG[4] SEG[5] CkLcd Frame COM1 COM2 COM1 VL3 COM3 VL2 COM4 VL1 VSS COM2 VL3 VL2 VL1 COM1 VL3 VL2 SEG[1] VL1 VSS COM3 VL3 VSS value = hex 0 -VL1 -VL2 -VL3 VL2 VL1 VSS COM4 VL3 COM1 VL3 VL2 SEG[2] VL1 VL2 VL1 VSS VSS value = hex 1 -VL1 -VL2 -VL3 SEG[1] VL3 value = hex 0 VL2 VL1 VSS COM2 VL3 VL2 SEG[3] VL1 VSS SEG[2] VL3 value = hex 1 VL2 value = hex 2 VL1 -VL1 -VL2 -VL3 VSS SEG[3] VL3 value = hex 2 VL2 COM3 VL3 VL2 SEG[4] VL1 VL1 VSS VSS value = hex 4 SEG[4] VL3 value = hex 4 -VL1 -VL2 -VL3 VL2 VL1 VSS COM4 VL3 VL2 SEG[5] VL1 SEG[5] VL3 value = hex 8 VL2 VL1 VSS value = hex 8 VSS Copyright © 2005, EM Microelectronic-Marin SA -VL1 -VL2 -VL3 50 www.emmicroelectronic.com R EM6521 15 Peripheral Memory Map Reset values are valid after power up or after every system reset. Register Name Ram1_0 Add Hex 00 Add Dec. 0 Reset Value b'3210 Read Bits 0: Data0 1: Data1 2: Data2 3: Data3 xxxx ... ... ... ... Ram1_63 3F 63 xxxx Write Bits Remarks Read / Write Bits Normal addressable Ram 64x4 bit ... 0: Data0 1: Data1 2: Data2 3: Data3 Normal addressable Ram 64x4 bit 0: Data0 1: Data1 2: Data2 3: Data3 16 nibbles addressable over index register on add 'H70 0: Data0 1: Data1 2: Data2 3: Data3 16 nibbles addressable over index register on add 'H70 Ram2_0 40 64 xxxx ... ... ... ... Ram2_3 43 67 xxxx LCD_1 44 68 xxxx Connections are user definable. See LCD section 16 nibbles addressable over index register on add 'H70 LCD_2 45 69 xxxx Connections are user definable. See LCD section 16 nibbles addressable over index register on add 'H70 xxxx Connections are user definable. See LCD section The 8 lower nibbles are addressable over the index register on add 'H70. The 8 higher Nibbles are not used and not implemented LCD_3 46 70 --- 47 71 Reserved, not implemented ... ... ... ... --- 4F 79 Reserved, not implemented RegPA 50 80 RegPBCntl 51 81 xxxx 0000 Copyright © 2005, EM Microelectronic-Marin SA 0: PAData[0] 1: PAData[1] 2: PAData[2] 3: PAData[3] ---0: PBIOCntl[0] 1: PBIOCntl[1] 2: PBIOCntl[2] 3: PBIOCntl[3] 51 Read port A directly Port B control Default: input mode www.emmicroelectronic.com R EM6521 Register Name Add Hex Add Dec. Reset Value b'3210 RegPBData 52 82 0000 RegSCntl1 53 83 0000 RegSCntl2 54 84 0000 RegSDataL 55 85 0000 RegSDataH 56 86 0000 RegSPData 57 87 0000 RegMelFSel 58 88 0000 RegMelTim 59 89 0000 RegMelPeri 5A 90 0000 RegCCntl1 5B 91 0000 RegCCntl2 5C 92 0000 RegCDataL 5D 93 0000 RegCDataM 5E 94 0000 RegCDataH 5F 95 0000 Copyright © 2005, EM Microelectronic-Marin SA Read Bits Write Bits Read / Write Bits 0: PBData[0] 1: PBData[1] 2: PBData[2] 3: PBData[3] 0: MSBnLSB 1: POSnNeg 2: MS0 3: MS1 0: OM[0] 1: OM[1] 2: Status 3: Start 0: SerDataL[0] 1: SerDataL[1] 2: SerDataL[2] 3: SerDataL[3] 0: SerDataH[0] 1: SerDataH[1] 2: SerDataH[2] 3: SerDataH[3] 0: PSP[0] 0: SerPData[0] 1: PSP[1] 1: SerPData[1] 2: PSP[2] 2: SerPData[2] 3: PSP[3] 3: SerPData[3] 0: MelFSel[0] 1: MelFSel[1] 2: MelFSel[2] 3: BzOutEn 0:FTimSel0 0:FTimSel0 1:FTimSel1 1:FTimSel1 2:Auto 2:Auto 3:FlBuzzer 3:SwBuzzer 0: 0: Per[0] 1: 1: Per[1] 2: 2: Per[2] 3: 3: Per[3] 0: CountFSel0 1: CountFSel1 2: CountFSel2 3: UP/Down 0: '0' 0 : Load 1: EnComp 1: EnComp 2: EvCount 2: EvCount 3: Start 3: Start 0: Count[0] 0: CReg[0] 1: Count[1] 1: CReg[1] 2: Count[2] 2: CReg[2] 3: Count[3] 3: CReg[3] 0: Count[4] 0: CReg[4] 1: Count[5] 1: CReg[5] 2: Count[6] 2: CReg[6] 3: Count[7] 3: CReg[7] 0: Count[8] 0: CReg[8] 1: Count[9] 1: CReg[9] 2: BitSel[0] 2: BitSel[0] 3: BitSel[1] 3: BitSel[1] 0: PB[0] 1: PB[1] 2: PB[2] 3: PB[3] 52 Remarks Port B data output Pin port B read Default : 0 Serial interface control 1 Serial interface control 2 Serial interface low data nibble Serial interface high data nibble Serial interface parallel data out Melody frequency select and output enable control Melody timer control Melody timer period 10-bit counter control 1; frequency and up/down 10-bit counter control 2; comparison, event counter and start 10-bit counter data low nibble 10-bit counter data middle nibble 10 bit counter data high bits www.emmicroelectronic.com R EM6521 Register Name Add Hex Add Dec. RegMSCCntl1 60 96 RegMSCCntl2 61 97 RegMSCDataL 62 98 RegMSCDataM 63 99 RegMSCDataH 64 100 RegIRQMask1 65 101 RegIRQMask2 66 102 RegIRQMask3 67 103 RegIRQ1 68 104 REgIRQ2 69 105 RegIRQ3 6A 106 RegSysCntl1 6B 107 RegSysCntl2 6C 108 Reset Value b'3210 Read Bits Write Bits Read / Write Bits 0: '0' 0: ResMSC 1: dT/MSC 1: dT/MSC 0000 2: PA3/µP 2: PA3/µP 3:RunEn/Stop 3:RunEn/Stop 0: FlSec 0: -1: IntSel 1: IntSel 0000 2: PA3Edge 2: PA3Edge 3: DebFreqSel 3: DebFreqSel 0: BCD[0] 0: 1: BCD[1] 1: 0000 2: BCD[2] 2: 3: BCD[3] 3: 0: BCD[4] 0: 1: BCD[5] 1: 0000 2: BCD[6] 2: 3: BCD[7] 3: 0: BCD[8] 0: 1: BCD[9] 1: 0000 2: BCD[10] 2: 3: BCD[11] 3: 0: MaskIRQPA[0] 1: MaskIRQPA[1] 0000 2: MaskIRQPA[2] 3: MaskIRQPA[3] 0: MaskIRQBz 1: MaskIRQBlink 0000 2: MaskIRQHz32/8 3: MaskIRQHz1 0: MaskIRQCntComp 0000 1: MaskIRQCount0 2: MaskIRQMSC 3: MaskIRQSerial 0: IRQPA[0] 0:RIRQPA[0] 1: IRQPA[1] 1:RIRQPA[1] 0000 2: IRQPA[2] 2:RIRQPA[2] 3:IRQPA[3] 3:RIRQPA[3] 0: IRQBz 0:RIRQBz 1: IRQBlink 1:RIRQBlink 0000 2: IRQHz32/8 2:RIRQHz32/8 3: IRQHz1 3:RIRQHz1 0:IRQCntComp 0:RIRQCntComp 1: IRQCount0 1:RIRQCount0 0000 2: IRQMSC 2:RIRQMSC 3: IRQSerial 3:RIRQSerial 0: ChTmDis 0: ChTmDis 0000 1: SelIntFull 1: SelIntFull 2: '0' 2: Sleep 3: IntEn 3: IntEn 0: WDVal0 0: -0p00 1: WDVal1 1: -2: SleepEn 2: SleepEn p = POR 3: '0' 3: WDReset Copyright © 2005, EM Microelectronic-Marin SA 53 Remarks millisecond counter control register 1; reset, delta time, control source Millisecond counter control register 2; 1 sec flag, Interrupt and PA3 edge select Millisecond counter; binary coded decimal value, low nibble Millisecond counter; binary coded decimal value, middle nibble Millisecond counter; binary coded decimal value, high nibble Port A interrupt mask; masking active 0 Buzzer and prescaler interrupt mask; masking active low 10-bit counter, millisecond counter, serial interrupt mask masking active low Read: port A interrupt Write: Reset IRQ if data bit = 1. Read: buzzer and prescaler IRQ ; Write: Reset IRQ id data bit = 1 Read: 10-bit counter, millisecond counter, serial interrupt Write: Reset IRQ if data bit =1. System control 1 ChTmDis only usable only for EM test modes with Test=1 System control 2; watchdog value and periodical reset, enable sleep mode www.emmicroelectronic.com R EM6521 Register Name Add Hex Add Dec. Reset Value b'3210 RegPresc 6D 109 0000 IXLow 6E 110 xxxx IXHigh 6F 111 xxxx RegIndexAdr 70 112 0000 RegLCDCntl1 71 113 PP00 RegLCDCntl2 72 114 111P RegVldCntl 73 115 0000 RegVldLevel 74 116 x000 Read Bits Write Bits Read / Write Bits 0: DebSel 1: PrIntSel 2: ResPresc 3: PWMOn 0: IXLow[0] 1: IXLow[1] 2: IXLow[2] 3: IXLow[3] 0: IXHigh[4] 0: IXHigh[4] 1: IXHigh[5] 1: IXHigh[5] 2: IXHigh[6] 2: IXHigh[6] 3: '0' 3: -0: IndexAdr[0] 1: IndexAdr[1] 2: IndexAdr[2] 3: IndexAdr[3] 0: CkTripSel0 1: CkTripSel1 2: StrobeOutSel0 3: StrobeOutSel1 0: LCDExtSupply 1: Lcd4xMux 2: LCDOff 3: LCDBlank 0: NoLogicWD 0: NoLogicWD 1: NoOscWD 1: NoOscWD 2: VldBusy 2: VldStart 3: VldResult 3: -0: VldLevel0 1: VldLevel1 2: VldLevel2 3: -0: DebSel 1: PrIntSel 2: '0' 3: PWMOn Remarks Prescaler control; debouncer and prescaler interrupt select Internal µP index register low nibble; for µP indexed addressing Internal µP index register high nibble; for µP indexed addressing Indexed addressing register for 4x16 nibble RAM2 and 3x16 + 8 nibble LCD LCD control 0; multiplier clock and strobe output select LCD control 1; main selects Voltage level detector control Voltage level detector; detection level selection P = defined by POR (power on reset) Copyright © 2005, EM Microelectronic-Marin SA 54 www.emmicroelectronic.com R EM6521 16 Option Register Memory Map The values of the option registers are set by initial reset on power up and through write operations only. Other resets ; as reset from watchdog, reset from input port A, reset from pin RESET, etc. do not change the options register value. Register Name OPTDebIntPA Add Hex Add Dec. Reset Value b'3210 75 117 0000 76 118 0000 77 119 0000 78 120 0000 79 121 0000 7A 122 0000 7B 123 0000 OPT[3:0] OPTIntEdgPA OPT[7:4] OPTNoPullPA OPT[11:8] OPTNoPdPB OPT[15:12] OPTNchOpDPB OPT[19:16] OPTNchOpDPS OPT[23:20] OPTFSelPB OPT[31:28] OPTInpRSel1 OPTInpRSel2 OPTNoPdPS 7C 124 0000 7D 125 0000 7E 126 0000 7F 127 ---- OPT[35:32] RegTestEM Copyright © 2005, EM Microelectronic-Marin SA Read Bits Write Bits Read / Write Bits 0: NoDebIntPA[0] 1: NoDebIntPA[1] 2: NoDebIntPA[2] 3: NoDebIntPA[3] 0: IntEdgPA[0] 1: IntEdgPA[1] 2: IntEdgPA[2] 3: IntEdgPA[3] 0: NoPullPA[0] 1: NoPullPA[1] 2: NoPullPA[2] 3: NoPullPA[3] 0: NoPdPB[0] 1: NoPdPB[1] 2: NoPdPB[2] 3: NoPdPB[3] 0: NchOpDPB[0] 1: NchOpDPB[1] 2: NchOpDPB[2] 3: NchOpDPB[3] 0: NchOpDPS[0] 1: NchOpDPS[1] 2: NchOpDPS[2] 3: NchOpDPS[3] 0: PB1HzOut 1: PB1kHzOut 2: PB32kHzOut 3: InpResSleep 0: InpRes1PA[0] 1: InpRes1PA[1] 2: InpRes1PA[2] 3: InpRes1PA[3] 0: InpRes2PA[0] 1: InpRes2PA[1] 2: InpRes2PA[2] 3: InpRes2PA[3] 0: NoPdPS[0] 1: NoPdPS[1] 2: NoPdPS[2] 3: NoPdPS[3] ---- ---- 55 Remarks Debouncer on port A for interrupt gen. Default: debouncer on Interrupt edge select on port A. Default: pos. edge Pull-down selection on port A Default: pull-down Pull-down selection on port B Default: pull-down Nch. open drain output on port B Default: CMOS output Nch. open drain output on port serial Default: CMOS output Frequency output on port B, reset from sleep mode with port A Reset through port A inputs selection. Refer to reset part Reset through port A inputs selection. Refer to reset part No Pull-down on port SP Default: pull-down for EM test only; www.emmicroelectronic.com R EM6521 17 Active Supply Current Test For this purpose, five instructions at the end of the ROM will be added. Testloop: STI LDR NXORX JPZ JMP 00H, 0AH 1BH Testloop 00H To stay in the testloop, these values must be written in the corresponding addresses before jumping in the loop: 1BH: 32H: 6EH: 6FH: 0101b 1010b 0010b 0011b Free space after last instruction: JMP 00H (0000) Remark: empty space within the program are filled with NOP (FOFF). Copyright © 2005, EM Microelectronic-Marin SA 56 www.emmicroelectronic.com R EM6521 18 Mask Options Most options which in many µControllers are realized as metal mask options are directly user selectable with the option registers, therefore allowing a maximum freedom of choice .See chapter: Option Register Memory Map. The following options can be selected at the time of programming the metal mask ROM, except the LCD Segment allocation which is defined using the interconnect metal2 mask. The EM6521 is delivered with the default metal mask settings. If you need other mask settings please contact EM Microelectronic Marin SA 142H 18.1 Input / Output Ports 18.1.1 Port A Metal Options Figure 38. Port A Pull Options (For ROM Version) Pull-up or no pull-up can be selected for each port A input. A pull-up selection is excluding a pull-down on the same input. Pull-down (default) or no pull-down can be selected for each port A input. A pull-down selection is excluding a pull-up on the same input. The total pull value (pull-up or pulldown) is a series resistance out of the resistance R1 and the switching transistor. The default resistor R1 value is 100 KOhm. Input Circuitry Pull-up Control PA[n] Terminal VBAT MPAPUstrong[n] Strong Pull-up Resistor R1 100 KOhm OR No Pull-up No Pull-down MPAPDstrong[n] Strong Pull-down Pull-down Control Option Name MPAPD[3] MPAPD[2] MPAPD[1] MPAPD[0] Strong Pulldown Option Name MPAPU[3] MPAPU[2] MPAPU[1] MPAPU[0] 1 x x x x PA3 input pull-down PA2 input pull-down PA1 input pull-down PA0 input pull-down R1 Value Typ.100 k No Pulldown 3 100k 100k 100k 100k 4 Strong Pull-up R1 Value typ.100k No Pull-up 1 3 100k 100k 100k 100k 4 x x x x PA3 input pull-up PA2 input pull-up PA1 input pull-up PA0 input pull-up Copyright © 2005, EM Microelectronic-Marin SA 57 To select an option put an X in column 1,2 and 4 and reconfirm the R1 value in column 3. The default value is : Strong pull-down with R1=100 KOhm To select an option put an X in column 1,2 and 4 and reconfirm the R1 value in column 3. The default value is : No pull-up www.emmicroelectronic.com R EM6521 18.1.2 Port B Metal Options (For ROM Version) Pull-up or no pull-up can be selected for each port B input. The pull-up is only active in Nch. open drain mode. Pull-down or no pull-down can be selected for each port B input. Figure 39. Port B Pull Options Input Circuitry Pull-up Control The total pull value (pull-up or pulldown) is a series resistance out of the resistance R1 and the switching transistor. The default resistor R1 value is 100 KOhm. PB[n] Terminal VBAT MPBPUstrong[n] Strong Pull-up Resistor R1 100 KOhm OR No Pull-up No Pull-down MPBPDstrong[n] Strong Pull-down Pull-down Control Option Name MPBPD[3] MPBPD[2] MPBPD[1] MPBPD[0] Strong Pulldown Option Name MPBPU[3] MPBPU[2] MPBPU[1] MPBPU[0] 1 x x x x PB3 input pull-down PB2 input pull-down PB1 input pull-down PB0 input pull-down Strong Pull-up PB3 input pull-up PB2 input pull-up PB1 input pull-up PB0 input pull-up Copyright © 2005, EM Microelectronic-Marin SA 1 x x x x R1 Value Typ.100k No Pulldown 3 100k 100k 100k 100k 4 R1 value Typ. 100k NO Pull-up 3 100k 100k 100k 100k 4 To select an option put an X in column 1,2 and 4 and reconfirm the R1 value in column 3. The default value is : Strong pull-down with R1=100 KOhm To select an option put an X in column 1,2 and 4 and reconfirm the R1 value in column 3. The default value is : Strong pull-up with R1=100 KOhm 58 www.emmicroelectronic.com R EM6521 18.1.3 Port SP Metal Options (For ROM Version) Pull-up or no pull-up can be selected for each port SP input. The pull-up is only active in Nch. open drain mode. Pull-down or no pull-down can be selected for each port SP input. Figure 40. Port SP Pull Options Input Circuitry Pull-up Control The total pull value (pull-up or pulldown) is a series resistance out of the resistance R1 and the switching transistor. The default resistor R1 value is 100 KOhm. PSP[n] Terminal VBAT MPSPUstrong[n] Strong Pull-up Resistor R1 100 KOhm OR No Pull-up No Pull-down MPSPDstrong[n] Strong Pull-down Pull-down Control Option Name MPSPD[3] MPSPD[2] MPSPD[1] MPSPD[0] Strong Pulldown Option Name MPSPU[3] MPSPU[2] MPBPU[1] MPSPU[0] 1 x x x x PB3 input pull-down PB2 input pull-down PB1 input pull-down PB0 input pull-down Strong Pull-up 1 x x x x PB3 input pull-up PB2 input pull-up PB1 input pull-up PB0 input pull-up R1 Value Typ.100k No Pulldown 3 100k 100k 100k 100k 4 R1 value Typ. 100k NO Pull-up 3 100k 100k 100k 100k 4 To select an option put an X in column 1,2 and 4 and reconfirm the R1 value in column 3. The default value is : Strong pull-down with R1=100 KOhm To select an option put an X in column 1,2 and 4 and reconfirm the R1 value in column 3. The default value is : Strong pull-up with R1=100 KOhm 18.1.4 Voltage Regulator Option Option name MVreg Voltage Regulator Default value A YES Copyright © 2005, EM Microelectronic-Marin SA user value B (For ROM Version) By default the internal voltage regulator supplies the core logic the RAM and the ROM. With option MVreg(B) the regulator is cut and VBAT is supplying the core logic the ROM and the RAM. 59 www.emmicroelectronic.com R EM6521 18.1.5 Debouncer Frequency Option Option Name Debouncer freq. MDeb Default Value A Ck[11] User Value B (ROM version only) By default the debouncer frequency is Ck[11]. The user may choose Ck[14] instead of Ck[11]. Ck[14 ]corresponds to maximum 0.25ms debouncer time in case of a 32kHz oscillator. 18.1.6 User defined LCD Segment Allocation (For ROM version) If using a different Segment allocation from the one described in chapter 14.3 , one needs to fill in following table. The Segment allocation connection are realized with the interconnect Metal2 mask. 143H 4 times MUX 3 times MUX COM[1] COM[1] COM[2] COM[2] COM[3] COM[3] COM[4] -- SEG[1] SEG[2] SEG[3] SEG[4] SEG[5] SEG[6] SEG[7] SEG[8] SEG[9] SEG[10] SEG[11] SEG[12] SEG[13] SEG[14] SEG[15] SEG[16] SEG[17] SEG[18] SEG[19] SEG[20] The customer should specify the required options at the time of ordering. A copy of the pages 57 to 60, as well as the « Software ROM characteristic file » generated by the assembler (*.STA) should be attached to the order. 14H 145H Copyright © 2005, EM Microelectronic-Marin SA 60 www.emmicroelectronic.com R EM6521 19 Measured Electrical Behaviors 19.1 IDD Current I(V DD) CP U in A CTIV E m ode, V DD= 3.0V [uA ] I(V DD) CP U in A CTIV E m ode, V DD= 5.0V 13.0 [uA ] 12.0 18.0 17.0 11.0 16.0 10.0 15.0 9.0 14.0 -20 0 20 40 60 [°C] 80 -20 I(V DD) LCD Off, Halt M ode, V DD = 3.0V [uA ] 2000 40 60 [°C] 80 2200 2100 1900 2000 1800 1900 1700 1800 -20 0 20 40 60 [°C] 80 -20 I(V DD) S leep m ode, V DD = 3.0V 0 20 40 60 [°C] 80 60 [°C] 80 I(V DD) S leep m ode, V DD = 5.0V 125 [nA ] 20 I(V DD) LCD Off, Halt M ode, V DD = 5.0V 2100 [uA ] 0 [nA ] 100 125 100 75 75 50 50 25 25 -20 0 20 40 60 [°C] 80 -20 0 20 40 19.2 Regulator Voltage V reg V DD= 3.0V V reg Tem p = 25°C 2.4 [V ] [V ] 2.2 2.2 2.0 2.0 1.8 1.8 1.6 1.6 -20 0 20 40 60 1.5 [°C] 80 2 2.5 3 3.5 V DD 4 V reg Load Dependenc y [V ] 2.3 2 1.7 1.4 1.1 -40°C 25°C 85°C 0 100 200 300 400 uA 500 19.3 Pull Resistors P ull-Down P ortB ; V DD= 3.0V 150.0 [kOhm ] 125.0 [k Ohm ] 125 100.0 100 75.0 75 50.0 P ull-Up P ortB ; V DD= 3.0V 150 50 -40 -20 0 20 40 Copyright © 2005, EM Microelectronic-Marin SA 60 [°C] 80 -20 61 0 20 40 60 [°C] 80 www.emmicroelectronic.com R EM6521 19.4 Output currents IOL P ortB, V DS = 0.15V /0.3V /0.5V /1.0V; T= 25°C IOH P ortB ; V DS =0.15V /0.3V /0.5V /1V ; T= 25°C 2 20 [m A ] 16 3 4 5 [V ] 0 1V 0.15V -3 12 8 0.5V 4 0.3V 0.15V 0 2 3 0.5V -6 -9 [m A ] [V ] 4 0.3V 5 1V -12 IOL P ortB; V DD= 3.0V; V DS = 0.15/0.3/0.5/1.0V IOH P ortB ; V DD= 3.0V ; V DS = 0.15/0.3/0.5/1.0V -20 [m A ] 15 0 20 40 60 0 12 [°C] 80 0.15 0.3 -2 9 1.0 0.5 -4 6 0.5 0.3 0.15 3 0 -6 -8 [m A] -20 0 20 40 60 80 1.0 [°C] IOL P ortB; V DD= 5.0V; V DS = 0.15/0.3/0.5/1.0V -10 IOH P ortB ; V DD=5.0V ; V DS =0.15/0.3/0.5/1.0V -20 [m A ] 20 0 0 20 40 60 [°C] 80 0.15 16 -3 1.0 12 8 0.5 -6 0.5 0.3 0.15 4 0 0.3 -9 1.0 [m A ] -20 0 20 40 60 Copyright © 2005, EM Microelectronic-Marin SA 80 [°C] -12 62 www.emmicroelectronic.com R EM6521 20 EM6521 Electrical Specification 20.1 Absolute Maximum Ratings Min. Max. Units Power supply VDD - VSS - 0.2 + 6.0 V Input voltage VSS - 0,2 VDD +0,2 V Storage temperature - 40 + 125 °C Electrostatic discharge to -2000 +2000 V Mil-Std-883C method 3015.7 with ref. to VSS Maximum soldering conditions 10s x 250°C Stresses above these listed maximum ratings may cause permanent damage to the device. Exposure beyond specified electrical characteristics may affect device reliability or cause malfunction. 20.2 Handling Procedures This device has built-in protection against high static voltages or electric fields; however, anti-static precautions should be taken as for any other CMOS component. Unless otherwise specified, proper operation can only occur when all terminal voltages are kept within the supply voltage range. 20.3 Standard Operating Conditions Parameter MIN TYP MAX Unit Description Temperature 0 25 60 °C VDD _Range 2 3.0 5.5 V with internal voltage regulator VSS 0 V Reference terminal CVDDCA (note 1) 100 nF regulated voltage capacitor fq 32768 Hz nominal frequency Rqs 35 kOhm typical quartz serial resistance CL 8.2 pF typical quartz load capacitance df/f +/- 30 ppm quartz frequency tolerance Note 1: This capacitor filters switching noise from VDD to keep it away from the internal logic cells. In noisy systems the capacitor should be chosen bigger than minimum value. 20.4 DC Characteristics - Power Supply Conditions: VDD =3.0V, T=25°C, unless otherwise specified Parameter ACTIVE Supply Current (in active mode with LCD on) STANDBY Supply Current (in Halt mode, LCDOff) SLEEP Supply Current Conditions Symb. (note2,3) 0 ... 60°C (note2,3) IVDDa IVDDa IVDDh IVDDh IVDDs IVDDs 0 ... 60°C Min. Typ. Max. 11 15 16 3 3.5 0.3 0.5 2.0 1.8 Unit µA µA µA µA µA µA V V V 0.1 0 ... 60°C POR static level 0 ... 60°C, No Load on Vreg VPOR 1.6 RAM data retention 0 ... 60°C Vrd 1.6 Regulated voltage Halt Mode, No Load Vreg 2 2.3 Note 2: LCD Display NOT connected. Note 3: For test reasons, the user has to provide a test loop with successive writing and reading of two different addresses (5 instructions should be reserved for this measurement). Copyright © 2005, EM Microelectronic-Marin SA 63 www.emmicroelectronic.com R EM6521 20.5 Supply Voltage Level Detector Parameter Conditions Symbol Min. Typ. Max. SVLD voltage Level1 0 ... 60°C VSVLD1 3.65 4.01 4.35 SVLD voltage Level2 0 ... 60°C VSVLD2 2.70 2.99 3.27 SVLD voltage Level3 0 ... 60°C VSVLD3 2.20 2.42 2.65 SVLD voltage Level4 Note 4 VSVLD4 1.82 2.01 2.20 SVLD voltage Level5 Note 5 VSVLD5 1.62 1.77 1.93 SVLD voltage Level6 Note 5 VSVLD6 1.39 1.54 1.68 SVLD voltage Level7 Note 5 VSVLD7 1.25 1.37 1.49 SVLD voltage Level8 Note 5 VSVLD8 1.11 1.22 1.34 Temperature coefficient +/- 0.2 Note 4 : Level which may not be reached anymore because it can be lower than VDD min. Note 5 : This levels can not be reached with the EM6521, (software compatibility EM6621) Unit V V V V V V V V mV/°C 20.6 Oscillator Conditions: T=25°C (unless otherwise specified) Parameter Conditions Symb. Temperature stability Input capacitor Output capacitor Transconductance Oscillator start voltage Oscillator start time System start time (oscillator + cold start + reset) Oscillation detector frequency +15 ... +35 °C Ref VSS Ref VSS 50mVpp, VDD min Tstart < 10 s VDD > VDD Min df/f x dT Cin Cout Gm Ustart tdosc tdsys VDD > VDD min tDetFreq Copyright © 2005, EM Microelectronic-Marin SA Min. 5,6 12,1 2.5 VDD min 64 Typ. Max. Unit 7 14 0,3 8,4 15,9 15.0 0.5 1.5 3 4 ppm /°C pF pF µA/V V s s 12 kHz www.emmicroelectronic.com R EM6521 20.7 DC characteristics - I/O Pins Conditions: T= 0 ... 60°C (unless otherwise specified) Parameter Conditions Symb Min. Typ. Max. Unit Ports A,B,SP,Test,Reset VIL VSS 0.3 VDD V QIN VIL VSS 0.1 Vreg V Ports A,B,SP,Test,Reset VIH 0.7 VDD VDD V QIN VIH 0.9 Vreg Vreg V Input Low voltage QOUT (note 7) Input High voltage QOUT (note 7) VDD =3.0V , VOL=0.15V IOL Port B,SP, VDD =3.0V , VOL =0.30V Strobe, VDD =3.0V , VOL =0.50V Buzzer VDD =3.0V , VOL =1.00V IOL Output High Current VDD =3.0V, VOH= VDD -0.15V Port B,SP, 1.8 mA IOL 3.6 mA IOL 5.8 mA 11.0 mA IOH -1.2 mA VDD =3.0V , VOH = VDD -0.30V IOH -2.4 mA Strobe, VDD =3.0V , VOH = VDD -0.50V IOH -3.9 mA Buzzer VDD =3.0V , VOH = VDD -1.00V IOH -7.0 Input Pull-down Test, Reset VDD =3.0V, Pin at 3.0V, 25°C RPD 15k Input Pull-down Port A,B,SP VDD =3.0V, Pin at 3.0V, 25°C RPD 70k 100k 130k Ohm Input Pull-up Port A,B,SP VDD =3.0V, Pin at 0.0V, 25°C RPU 72k 103k 134k Ohm Output Low Current 7 -4.5 mA Ohm Note 7 ; QOUT (OSC2) is used only with Quartz. Copyright © 2005, EM Microelectronic-Marin SA 65 www.emmicroelectronic.com R EM6521 20.8 LCD SEG[20:1] Outputs Conditions: T=25°C (unless otherwise specified) Parameter Conditions Symb. Min. Typ. Max. Unit Driver Impedance Level 0 Iout = ±5μA, Ext. Supply RSEGVL0 20 KOhm Driver Impedance Level 1 Iout = ±5μA, Ext Supply RSEGVL1 20 KOhm Driver Impedance Level 2 Iout = ±5μA, Ext Supply RSEGVL2 20 KOhm Driver Impedance Level 3 Iout = ±5μA, Ext Supply RSEGVL3 20 KOhm Max. 10 Unit KOhm 10 KOhm 10 KOhm 10 KOhm 20.9 LCD Com[4:1] Outputs Conditions: T=25°C (unless otherwise specified) Parameter Conditions Symb. Driver Impedance Level 0 RcomVL0 Iout = ±5μA, Ext. Supply Driver Impedance Level 1 RcomVL1 Iout = ±5μA, Ext. Supply Driver Impedance Level 2 RcomVL2 Iout = ±5μA, Ext Supply RcomVL3 Driver Impedance Level 3 Iout = ±5μA, Ext Supply Min. Typ. 20.10 DC Output Component Conditions: T=25°C (unless otherwise specified) Parameter Conditions Symb. DC Output component No Load Min. Typ. ±VDC_com Max. 20 Unit mV 20.11 LCD Voltage Multiplier Conditions: T=25°C, All Multiplier Capacitors 100nF, freq=512Hz. (unless otherwise specified) Parameter Conditions Symb. Min. Typ. Max. Voltage Bias Level 1 0.95 1.05 1.17 VVL1 1μA load Unit V Voltage Bias Level 2 1μA load VVL2 2.10 V Voltage Bias Level 3 1μA load VVL3 3.15 V Temp dependency VvL1 1μA load, 0 ... 60°C dVVL1/dT -4.9 mV/°C Copyright © 2005, EM Microelectronic-Marin SA 66 www.emmicroelectronic.com R EM6521 21 Pad Location Diagram Copyright © 2005, EM Microelectronic-Marin SA 67 www.emmicroelectronic.com R EM6521 22 Package & Ordering information The default package for the EM6521 microcontroller is the TQPF52 10x10x1 mm. TOP VIEW D ODD LEAD SIDES EVEN LEAD SIDES e b D1 DETAIL "A" e SEE DETAIL "A" S Y M B O L A TQFP52 ALL DIMENSIONS IN MILLIMETERS MIN. TYP. MAX. 1.20 A A1 SEE DETAIL "B" 0.05 1.0 A2 DETAIL "B" 0.15 D 12.00 BSC. D1 10.00 BSC. 0° MIN. L 0.08/0.20 R. A2 0.08 R. MIN. 0.20 MIN. 0.60 0.75 52 0.65 BSC e b A1 0.45 N 0.22 0.32 0.38 0-7° L 1.00 REF. 1.00/0.10 MM FORM, 1.0 MM THICK PACKAGE OUTLINE, TQFP, 10X10 MM BODY, 22.1 Ordering Information Ordering Part Number Part Number Package/Die Form EM6521%%%TQ52D EM6521%%%WP11 TQFP 52 pin Die in waffle pack Delivery Form/ Thickness Trays (Plate) 11 mils Please make sure to give the complete Part Number when ordering, including the 3-digit version. The version is made of 3 digits %%%: the first one is a letter and the last two are numbers, e.g. P04 , P07, P12, etc. For other delivery forms, please contact EM Microelectronic-Marin S.A. Please contact EM headquarters or your local EM office for any other detail. Also refer to page 60 for additional ordering information. 146H EM Microelectronic-Marin SA (EM) makes no warranty for the use of its products, other than those expressly contained in the Company's standard warranty which is detailed in EM's General Terms of Sale located on the Company's web site. EM assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of EM are granted in connection with the sale of EM products, expressly or by implications. EM's products are not authorized for use as components in life support devices or systems. © EM Microelectronic-Marin SA, 01/06, Rev. F Copyright © 2005, EM Microelectronic-Marin SA 68 www.emmicroelectronic.com