ABRIDGED DATA SHEET 19-5893; Rev 0; 6/11 MAXQ1740 Magnetic Card Reader Security Microcontroller General Description Features The MAXQ1740 is a low-power microcontroller that integrates a triple-track magnetic stripe reader interface, an I2C interface, two SPIK interfaces, and one universal synchronous/asynchronous receiver-transmitter (USART) interface. Security features include an AES encryption engine, a true hardware random-number generator, voltage-attack sensors, and a self-destruct input pin. A single-cycle 16-bit RISC MAXQM CPU powers the device. It provides a high level of security for the magnetic stripe reader by placing an ultra-secure microcontroller with high-speed hardware encryption inside the magnetic card reader head. SCore Functionality High-Performance, Low-Power, 16-Bit MAXQ20C RISC Core 6MHz Internal Oscillator (±10%) Up to 12MHz External Crystal Supported 1.7V to 3.6V Operating Voltage 1-Wire® Interface for Debugger and Flash Programming Optimized for C-Compiler The device provides 16KB of flash memory, 1KB of fastwipe nonvolatile SRAM (NV SRAM), and 128 bytes of data NV SRAM that instantaneously zeroizes its contents when a tamper is detected. The 128 bytes can be used as data RAM or working RAM for the AES. The fast-wipe feature ensures that any data in the 1KB of memory is destroyed before any application software can access it. Factory programming of a unique 64-bit serial number, and/or customer secret key(s), is available upon request. The microcontroller runs within a wide 1.7V to 3.6V operating range. User-application firmware interfaces with the triple-track magnetic stripe interface. Reference software supports the reading of cards adhering to ISO 7811, ISO 7812, and ISO 7813. Source code to the reference software is available so applications can make adjustments for custom card formats. An ultra-low-power stop mode provides the ultimate in low-power performance. In this mode, only a minimum amount of circuitry is powered to support detection of self-destruct events. When the main power supply is present and the microcontroller is in stop mode, the device has the option of exiting stop mode when stimulated by general-purpose port pins or the serial interfaces. Applications ATM/POS Terminals Physical Security/Building Access SSecurity AES Hardware Accelerators Hardware True Random-Number Generator Self-Destruct Input for Tamper Detection Permanent Loader Lockout Option Code Scrambling SMemory 16KB Flash Memory 512 Bytes Memory Page Sectors 1000 Erase/Write Cycles per Sector 1152 Bytes Fast-Wipe NV SRAM, 128 Bytes Usable by Cryptographic Engine 6KB Utility ROM with User-Callable Routines SI/O and Peripherals Triple-Track Magnetic Stripe Head Interface Two SPI Communication Ports USART Communication Port Two 16-Bit Timers I2C Communication Port Up to 16 General-Purpose I/O Pins Up to 8 External Interrupt Pins SLow Power Consumption 3µA Current in Lowest Power Stop Mode 3.75mA (typ) at 6MHz, 0.8mA (typ) at 1MHz Divided System Clock Modes Available SAdditional Peripherals On-Chip Power-On/Power-Fail Reset Supply Overvoltage Detection Programmable Watchdog Timer Wake-Up Timer Ordering Information appears at end of data sheet. SPI is a trademark of Motorola, Inc. MAXQ and 1-Wire are registered trademarks of Maxim Integrated Products, Inc. For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/MAXQ1740.related Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, go to: www.maxim-ic.com/errata. ����������������������������������������������������������������� Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. ABRIDGED DATA SHEET MAXQ1740 Magnetic Card Reader Security Microcontroller Block Diagram WAKE-UP TIMER 16KB FLASH MEMORY 16-BIT TIMER 1024B FAST-ERASE DATA NV SRAM 16-BIT TIMER 256B FAST-WIPE DATA/AES NV SRAM SELFDESTRUCT INPUT USART AES ENCRYPTION ENGINE 6KB UTILITY ROM 1-Wire INTERFACE MAXQ RISC CPU 3-TRACK MAG STRIPE INTERFACE WATCHDOG TIMER INTERNAL VOLTAGE 6MHz MONITOR/ OSCILLATOR REGULATOR RANDOMNUMBER GENERATOR MAXQ1740 I2C SPI SPI GPIO UP TO 16 GND +1.7V TO +3.6V Detailed Description Microprocessor The MAXQ20C core supports the Harvard memory architecture with separate 16-bit program and data address buses. A fixed 16-bit instruction word is standard, but data can be arranged in 8 or 16 bits. The MAXQ core is implemented as a pipelined processor with performance approaching 1MIPS per MHz. The 16-bit data path is implemented around register modules, and each register module contributes specific functions to the core. The accumulator module consists of sixteen 16-bit registers and is tightly coupled with the arithmetic logic unit (ALU). Program flow is supported by a configurable soft stack. Execution of instructions is triggered by data transfer between functional register modules, or between a functional register module and memory. Since data movement involves only source and destination modules, circuit switching activities are limited to active modules only. For power-conscious applications, this approach localizes power dissipation and minimizes switching noise. The modular architecture also provides a maximum of flexibility and reusability that are important for a microprocessor used in embedded applications. The MAXQ1740 is a MAXQ20C-based microcontroller intended for integration into magnetic card readers. It can be interfaced directly to a 3-track magnetic card reader head, allowing security features to be added to a POS or ATM card reader right at the machine/card interface. Encryption is provided by a hardware AES engine. Security features include a self-destruct input for tamper detection, code scrambling, and fast-wiping of the NV SRAM in the event of a tamper detection and supplyrail monitoring for overvoltage conditions. A 16KB flash memory provides nonvolatile storage for user programs and other static, nonvolatile data. The MAXQ instruction set is highly orthogonal. All arithmetic and logical operations can use any register in conjunction with the accumulator. Data movement is supported from any register to any other register. Memory is accessed through specific data pointer registers with auto increment/decrement support. The device provides 1KB of fast-wipe NV SRAM and 128 bytes of data NV SRAM, which instantaneously zeroizes its contents when a tamper is detected. The 128 byytes can be used as data RAM or working RAM for the AES. The fast-wipe feature ensures that any data in the 1KB of memory is destroyed before any application software can access it. Communication peripherals include a hardware I2C, a hardware USART, and two hardware SPIs. A 1-Wire port is available for system programming and application debugging. • 128 bytes of instantaneous zeroization NV SRAM Memory The microcontroller incorporates several memory types: • 16KB flash memory • 1152 bytes fast-wipe NV SRAM • 6KB utility ROM • RAM-based software stack The NV SRAM is cleared by a DRS event. The 128-byte memory can be used as general-purpose memory if the AES function is not in use. Starting the AES engine invalidates data stored in this memory. See Figure 5 for the memory map. ���������������������������������������������������������������� Maxim Integrated Products 11 ABRIDGED DATA SHEET MAXQ1740 Magnetic Card Reader Security Microcontroller Applications Information Additional Documentation The low-power, high-performance RISC architecture of this device makes it an excellent fit for many portable or battery-powered applications requiring security. Designers must have the following documents to fully use all the features of this device. This data sheet contains pin descriptions, feature overviews, and electrical specifications. Errata sheets contain deviations from published specifications. The user’s guides offer detailed information about device features and operation. Grounds and Bypassing Careful PCB layout significantly minimizes system-level digital noise that could interact with the microcontroller or peripheral components. The use of multilayer boards is essential to allow the use of dedicated power planes. The area under any digital components should be a continuous ground plane if possible. Keep any bypass capacitor leads short for best noise rejection and place the capacitors as close as possible to the leads of the device. CMOS design guidelines for any semiconductor require that no pin be taken above VDD or below GND. Violation of this guideline can result in a hard failure (damage to the silicon inside the device) or a soft failure (unintentional modification of memory contents). Voltage spikes above or below the device’s absolute maximum ratings can potentially cause a catastrophic latchup of the device. Microcontrollers commonly experience negative voltage spikes through either their power pins or generalpurpose I/O pins. Negative voltage spikes on power pins are especially problematic as they directly couple to the internal power buses. Devices such as keypads can conduct electrostatic discharges directly into the microcontroller and seriously damage the device. System designers must protect components against these transients that can corrupt system memory. • This MAXQ1740 data sheet, which contains electrical/ timing specifications and pin descriptions. • The revision-specific MAXQ1740 errata sheet. • The MAXQ1740 User’s Guide, which contains detailed information on core features and operation, including programming. Development and Technical Support A variety of highly versatile, affordably-priced development tools for this microcontroller are available from Maxim and third-party suppliers, including: • Compilers • In-circuit emulators • Integrated development environments (IDEs) A partial list of development tool vendors can be found at www.maxim-ic.com/MAXQ_tools. For technical support, go to https://support.maxim-ic. com/micro. Ordering Information TEMP RANGE OPERATING VOLTAGE (V) FLASH MEMORY (KB) DATA MEMORY (KB) MAXQ1740-FBX+ 0NC to +70NC 1.70 to 3.6 16 1 28 TQFN-EP* MAXQ1740-DNS+ 0NC to +70NC 1.70 to 3.6 16 1 Bare die PART +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. PIN-PACKAGE Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 28 TQFN-EP T2844+1 21-0139 90-0035 Note to readers: This document is an abridged version of the full data sheet. To request the full data sheet, go to www.maxim-ic.com/MAXQ1740 and click on Request Full Data Sheet. ���������������������������������������������������������������� Maxim Integrated Products 22