Abstract: Many digital devices incorporate analog circuits. For instance, microprocessors, applicationspecificintegrated circuits (ASICs), and field-programmable gate Arrays (FPGAs) may have internalvoltage references, analog-to-digital converters (ADCs) or digital-to-analog converters (DACs). However,there are challenges when you integrate more analog onto a digital design. As with all things in life, inelectronics we must always trade one parameter for another, with the application dictating the propertrade-off of analog function. In this application note, we examine how the demand for economy of spaceand cost pushes analog circuits onto digital substrates, and what design challenges emerge.
標簽：
模擬IC
性能
模擬
數(shù)字化設(shè)計
上傳時間：
2013-11-17
上傳用戶：菁菁聆聽
The μPSD32xx family, from ST, consists of Flash programmable system devices with a 8032 MicrocontrollerCore. Of these, the μPSD3234A and μPSD3254A are notable for having a complete implementationof the USB hardware directly on the chip, complying with the Universal Serial Bus Specification, Revision1.1.This application note describes a demonstration program that has been written for the DK3200 hardwaredemonstration kit (incorporating a μPSD3234A device). It gives the user an idea of how simple it is to workwith the device, using the HID class as a ready-made device driver for the USB connection.IN-APPLICATION-PROGRAMMING (IAP) AND IN-SYSTEM-PROGRAMMING (ISP)Since the μPSD contains two independent Flash memory Arrays, the Micro Controller Unit (MCU) can executecode from one memory while erasing and programming the other. Product firmware updates in thefield can be reliably performed over any communication channel (such as CAN, Ethernet, UART, J1850)using this unique architecture. For In-Application-Programming (IAP), all code is updated through theMCU. The main advantage for the user is that the firmware can be updated remotely. The target applicationruns and takes care on its own program code and data memory.IAP is not the only method to program the firmware in μPSD devices. They can also be programmed usingIn-System-Programming (ISP). A IEEE1149.1-compliant JTAG interface is included on the μPSD. Withthis, the entire device can be rapidly programmed while soldered to the circuit board (Main Flash memory,Secondary Boot Flash memory, the PLD, and all configuration areas). This requires no MCU participation.The MCU is completely bypassed. So, the μPSD can be programmed or reprogrammed any time, anywhere, even when completely uncommitted.Both methods take place with the device in its normal hardware environment, soldered to a printed circuitboard. The IAP method cannot be used without previous use of ISP, because IAP utilizes a small amountof resident code to receive the service commands, and to perform the desired operations.
標簽：
Demonstration
3200
USB
for
上傳時間：
2014-02-27
上傳用戶：zhangzhenyu
