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Anleitung Zusammenfassung
1. General questions 1. What is the MAX3420E? 2. Does the MAX3420E include a microprocessor? 3. What packages are available for the MAX3420E? 4. Are the MAX3420E packages lead-free? 2. USB questions 1. What USB speeds does the MAX3420E support? 2. Does the MAX3420E comply with the USB spec? Which revision? 3. How many endpoints does the MAX3420E support? 4. Why doesn't the MAX3420E support isochronous transfers? 5. Can I use the MAX3420E in a self-powered peripheral? 6. Can I use the MAX3420E in a bus-powered peripheral? 7. What external circuitry do I need to connect the MAX3420E to USB? 8. Can you recommend a 3.3V regulator? 9. What does the CONNECT bit do? 3. Interface questions 1. How does a microprocessor connect to the MAX3420E? 2. You say the SPI interface is 3, 4 or 5 wires. What does this mean? 3. What SPI clocking modes does the MAX3420E support? 4. My CPU uses a 2.5 volt supply, but the MAX3420E uses a 3.3V VCC supply. Do I need external level translators? 5. What is the purpose of the MAX3420E INT pin? 6. Does the MAX3420E support active-low wired-OR interrupts? How about edge active interrupts? 7. How fast can I run the MAX3420E SPI interface (SCLK max frequency)? 8. Is there a low limit to the MAX3420E SCLK frequency? 9. I have an 8-pin microprocessor, and it takes 5 of its' IO pins to connect to the MAX3420E. How do I do IO? 10. Do I need to add external pullup resistors to the GPIN pins? 11. Can I drive optocouplers from the SPI interface pins? 12. What is the purpose of the VBCOMP pin? Does it power the MAX3420E? 4. Programming questions 1. How does my firmware talk to the MAX3420E? 2. How do I program the MAX3420E to handle USB enumeration? 3. How do I program a BULK IN transfer? 4. What if a USB IN request comes in while firmware is loading the IN FIFO? 5. How do I know when to load an IN FIFO? 6. What if there is a USB transfer error? Do I need to write code to handle the error condition? 7. How do I program a BULK OUT transfer? 8. How about INTERRUPT transfers? 9. How do I program a SETUP transfer? 10. Do I need to program the USB data toggles? 11. The MAX3420E interrupt request bits are cleared by writing "1" to them. Is this backwards? 12. Do you have any programming tips? 5. Host software questions 1. How does my Windows application talk to the MAX3420E? 2. Does Maxim supply a custom Windows driver? 3. What example code does Maxim supply? 4. I want to design a MAX3420E-based device that does not conform to a standard Windows class. What do I use for a Windows driver? 5. How does the MAX3420E compare with USB 'serial bridge' chips? 6. What are the advantages and disadvantages of the MAX3420E approach? 6. Miscellaneous questions 1. Can my firmware determine which chip revision I have? 2. What is the current revision level of the MAX3420E? 1. General Questions 1. What is the MAX3420E? The MAX3420E is a USB full-speed (12Mbps) peripheral controller with a built-in transceiver and a USB serial interface engine (SIE) that handles the low-level USB signaling details. 2. Does the MAX3420E include a microprocessor? No. The MAX3420E is designed to interface easily to any microprocessor, DSP, or ASIC. This makes it possible to add USB to any system without switching processors or tool sets. 3. What packages are available for the MAX3420E? The MAX3420E is available in two packages. The 32-pin TQFP (7mm x 7mm body size) is good for prototyping and short production runs because it has package leads. The 24-pin TQFN package (5mm x 5mm body size, pads underneath the package) is ideal for highvolume compact devices. 4. Are the MAX3420E packages lead-free? Yes. 2. USB Questions 1. What USB speeds does the MAX3420E support? The MAX3420E supports USB full-speed (12Mbps) operation as a peripheral. 2. Does the MAX3420E comply with the USB spec? Which revision? The MAX3420E is compliant with the USB 2.0 specification as it applies to full-speed operation. 3. How many endpoints does the MAX3420E support? The MAX3420E contains four endpoints: EP0, bidirectional CONTROL endpoint, 64 byte FIFO. EP1, OUT BULK or INT endpoint, 2 x 64 byte double-buffered FIFOS EP2, IN BULK or INT endpoint, 2 x 64 byte double-buffered FIFOS EP3, IN BULK or INT endpoint, 64 byte FIFO With these endpoints, it is possible to build USB peripherals that support popular USB class drivers, such as a Human Interface Device (HID), Mass Storage, Picture Transfer Protocol (PTP), and Printer. 4. Why does the MAX3420E not support ISOCHRONOUS transfers? ISOCHRONOUS transfers require fast interfaces and large buffers, neither of which is consistent with the MAX3420E design goals (a low-cost part with an SPI interface that can run at any speed). Most applications that seem to require ISOCHRONOUS bandwidth can actually be handled with BULK or INTERRUPT transfers. This is because most of the ISOCHRONOUS bandwidth available to a USB device in a system is also typically available for BULK/INT transfers. 5. Can I use the MAX3420E in a self-powered pe...