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USB 1.1 Full and Low Speed Devices
When someone says USB Microcontroller, Cypress normally springs to everyone’s mind. No wonder when Cypress has an extensive range of USB Microcontrollers in both 1.5Mbps, 12Mbps and 480Mbps versions. They have acquired AnchorChips and it's EzUSB range and last year also acquired ScanLogic which has helped to prop up their range of USB controllers. This range starts with the Cypress M8 Series which is predominantly low speed 1.5Mbps controllers for low speed devices such as mice and keyboards. They have added two full speed devices to the M8 range, the CY7C64013 and the CY7C64113. More recently they have added a enCoRe range to their books. CY7C63001 Should you wish to extend to higher speed devices, Cypress’s High Speed USB MCU’s requires specialised programmers and development tools that come at great cost. Cypress is a good start, should your company desire to sink a bit of money for some nice toys. Cypress Semiconductor brought out Anchor Chip's EzUSB Series. Anchor had taken initiative in the USB market with some smart features. One of these was it's Re-numeration(TM) which allows it's processor to operate without ROM, EPROM or FLASH. It does this by automatically enumerating without firmware as a "Default Anchor Device". This then allows you to download 8051 code to the processor, then renumerate with your newly downloaded code. This is not only a sought after feature during development, but can also be used in the field as a means of a re-configurable device or having the ability to download the code each time the device is used to ensure the firmware is up to date. Extending on this, EzUSB also has the ability to do enumeration in silicon, thus making your coding of the enumeration process a breeze. EZ-USB Family (AN21XX) Cypress has enhanced the EzUSB series, bringing out the EZ-USB FX Series. (They have re-introduced the CY7C64xxx part number of course). EZ-USB FX Family (CY7C646xx) USB I2C/IO Interface Board by DeVaSys
Microchip Microchip has been late to enter the market with their USB Microcontrollers. Based on their popular PIC16x series devices, these USB controllers use traditional windowed devices for development rather than Flash which is common among the newer PIC Micro's. Being a low speed device, you would have to look closely at their feasibility as they don't support Bulk nor Isochronous transfers and they are UV Erasable instead of Flash. However these devices are very easy to purchase with both RS and Farnell selling them in one off quantities. Given the success of Microchip's 16F877/876 series complete with ICD (In-CIrcuit Debugger) it's possible that a PDIUSBD11 or 12 hanging off ports make it an better option for the time being.
PIC16C745 PIC16C765 Microchip have released details of their future products which is sure to keep any Microchip follower happy. They are full speed flash devices with support for the In-Circuit Debugger. While that may be enough to win the hearts of some, I like the 18Fxxx architecture which means linear program and data memory. Yes, no more paging!. PIC18F2X50 PIC18F4X50 NetChip Technology, Inc NetChip provides two USB 1.1 peripheral controllers as well as a function specific NET1031 Single Chip USB Scanner Controller and a NET1080 TurboConnect Single Chip Host to Host Device. NET2888 TurboUSB Full Speed Programmable Peripheral Controller TurboUSB is one of NetChip's first USB controllers which has been shipping in production volume since April 1997. NET2890 FlexUSB Full Speed Programmable Peripheral Controller An upgrade path to the TurboUSB NET2888 is the pin to pin compatable NET2890 Peripheral Controller. It provides 4 configurable endpoints with the performance of both CPU and DMA transfers. Motorola has had since 1997, the 68HC705JB2, a 20 pin Low Speed USB MCU based on their popular HC05 Core. However since late 1997, I’ve been trying to source them. . . . Some distributors have a small quantity (5-10) of the OTP parts, but this is not much good if you can’t source a windowed device for development. Too bad they are Obsolete now. I may try for some 68HC705JB3 / JB4's now . . . 68HC705JB2 Obsolete / Discontinued
Motorola have just recently extended their MCU range to include a JB3 & JB4.
These are again low speed devices coming in a 20 or 28 pin package. These are
prequalified parts and Motorola should start production of these IC’s any day
now. (April/May 1999).
68HC705JB3 68HC705JB4 Philips Semiconductor Philips has a nice alternative - A add on full speed USB Device. The problem with low speed USB Devices, is the restriction of transfer modes. A full speed device can use Isochronous, Control, Interrupt or Bulk transfer modes. A low speed device is restricted to Control & Interrupt Modes. Therefore by Philip's making their Serial USB Device Full Speed, even though the I2C interface is limited to 1Mbps, the designer has the added flexibility of most transfer modes (except Isochronous on the PDIUSBD11). Other added advantages are - why waste time learning a new architecture? With the USB Interface I.C.’s you can use your existing designs, existing code and existing development tools. All you need to do is modify the design to hang the USB Device of the bus. What could be cheaper?
PDIUSBD11 - USB Interface Device with Serial Interface PDIUSBD12 - USB Interface Device with Parallel Bus There are disadvantages to these devices, namely board real estate. You wouldn’t make a USB Mouse with these chips. However both come in surface mount devices giving a very small footprint. They are also not intended for self powered devices. I’m finding the Philip's I.C.’s difficult to source. Some of these manufacturers should look at Maxim’s Small Credit Card Order Facilities. On other thoughts, maybe we should encourage Maxim to make a USB Serial Interface Engine! (23/05/2002 - Maxim has introduced a future product, the MAX3340E/MAX3341E ESD Protected USB Level Translators.) Philips also has a USB Transceiver Chip, the PDIUSBP11. This I.C. will convert USB into a Digital CMOS Serial stream. Couple this with a FPGA or CPLD and write your own Serial Interface Engine. PDIUSBP11 - Universal Serial Bus transceiver
A special thanks to Michael DeVault from DeVaSys Embedded Systems for sending out a USB I2C/IO Interface Board, USBLPT-PD11 USB development board (desktop version) and a USBLPT-PD11D, USB development board (dongle version) for evaluation.
Philips have released the ISP1161 - the world's first single-chip, integrated host and device controller conforming to the USB Revision 1.1. It has been used by Philips to demonstrate USB OTG functionallity, but also makes an excellent host controller for embedded systems such as Linux. See our write-up of the On-The-Go Supplement - Point-to-Point Connectivity for USB and further details of this device. ISP1161 Full-speed Universal Serial Bus single-chip host and device controller. FTDI Future Technology Devices International FTDI specialises in converting legacy peripherals to Universal Serial Bus. They offer two devices, one is a USB to asynchronous comms (RS-232) interface and the other a USB to byte wide FIFO. Due to their ease of use, they are not only useful for upgrading legacy designs but also for new designs. See our detailed article on these devices, USB with the simplicity of RS-232 FT8U232AM - USB UltraBaud Transfer IC with RS-232/RS422 and CPU I/F Options FT8U245AM - Fast Parallel Data Transfer IC FT232BM and FT245BM 2nd Generation Devices FTDI is in the process of announcing their second generation of '232 and '245 chips which will begin sampling early in Q3, 2002 and cost about the same than the first generation. Their additional features include, Add USB in 10 minutes! If you wish to try these FTDI devices out before committing them to your design, then you can get prebuilt prototyping modules from Elexol. These modules are available in both serial and parallel interface versions. This makes them an ideal USB add on solution for Microchip, AVR and other microprocessors. The serial version gives you the flexibility of adding it to your existing asynchronous comms port leaving the parallel I/O ports free or if you need speed, you can use the USBMOD2 with a parallel interface capable of 1Mbyte/sec. The 32-pin 600mil IC socket profile allows them to be plugged into phototyping boards with ease.
A special thanks to Brenden Ede from Gigatechnology.com for sending out a USBMOD USB to TTL Serial and USBMOD2 USB to 8 bit Parallel Data module. They have been an invaluable addition to my toolbox. Not only is it much faster than prototyping with a MAX232 on prototyping board, it's also USB and works with both my Windows and Linux Platforms. The I/O Warrior from Code Mercenaries is a quick and easy way to add USB to your products without having to understand the USB specification or write custom firmware and device drivers. Two programmed devices are available, a 24 pin version and a larger 40 pin version, both enumerating as a common HID device. The unique feature of these devices is the built in support for various industry standard protocols such as I2C, SPI, HD44780 Alphanumeric LCDs, RC5 code IR remote controls, matrix scanning of keypads and driving of LEDs. The manual also comes with details on how to drive relays, LEDs and opto-isolating inputs and outputs. IOWarrior 24IOWarrior 40 I/O Warriors can be purchased in I.C. form for quick integration into your designs. Code Mercenaries also has two development boards for quick evaluation and phototyping.  The U401 is a simple USB I/O Digital Interface which is SimmStick(TM) Compatible. It provides 16 I/O lines which can be individually set as inputs or outputs. It can be used as a interface to SPI devices with an adjustable clock rate of 62.5 kHz, 500 kHz, 1 MHz, or 2 MHz, or it can be used with LCD panels and a whole host of other uses. What more, there is no firmware or any device drivers to write and debug. This allows the U401 to be effortlessly used as an simple PC interface in the minimal time. The USBmicro Online Development Notebook gives details of the API. National Semiconductor National Semiconductor has the USBN960x series of USB devices which can be connected up to your micro, just like the Philip's devices could. This gives you the ability to make your existing microcontrollers talk USB without the need for a new set of development tools or training in a new architecture. NatSemi has combined both a serial and parallel interface version into the one I.C., which makes sense when it comes to needing to stock only the one I.C. for all your USB projects. National Semiconductor's devices are normally easier to obtain than Philips parts and the datasheets are well written, making this option more attractive if you are having trouble either sourcing Philip’s ICs or interpreting their datasheets.USBN9603 /USBN9604 Full Speed Node Controller with Enhanced DMA SupportThey also have an older USBN9602. The biggest problem with this part was it’s 48MHz Oscillator. The Philip's devices at the time used a PLL to generate the 48MHz internal Clock. The result, a cheap 6 or 12Mhz Crystal could be used helping with the EMC compliance. This part is no longer recommended for new designs. USBN9602 USB Full Speed USB Device
USB Protocol Analysers Additional USB Resources |
