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本人正从M3平台（LM3S9B90）移植到M4平台（TM4C1294K）中，EPI应用中遇到问题，M3平台上使用EPI没有问题。
移植过程中，M4平台的EPI配置与M3的是一样的，但就是不能正常工作。请大家帮忙看看哪里出现问题了。
EPI配置为HB8模式，ALE+双CSn，使能字访问。
具体 初始化函数请看附件：M3InitEPI（）为M3平台正常使用的函数，M4InitEPI（）为M4平台正常使用的函数，两个平台外围硬件是一样的，唯一区别就是MCU不一样。EPI接口连接外设和RAM
xyz549040622：
The EPI module on Tiva C Series devices is compatible with the EPI module on LM3S devices, and offersadditional features such as higher speed, support for PSRAM, bursting, additional chip selects and more.The EPI module has no significant concerns when moving from LM3S to TM4C designs. For more designrecommendations, see the EPI section of the System Design Guidelines for the TM4C129x Family ofTiva™ C Series Microcontrollers (SPMA056). There are four changes that were made that could affectolder designs:• The WORD bit in the the EPI Host-Bus 8 Configuration 2 (EPIHB8CFG2), EPI Host-Bus 16Configuration 2 (EPIHB16CFG2), and EPI General-Purpose Configuration 2 (EPIGPCFG2) registershas been removed• The RD2CYC bit in the EPI General-Purpose Configuration (EPIGPCFG) register has been removed• iRDY operation is no longer supported in General Purpose mode• Dual chip select operation is no longer supported in Host Bus continuous read modeThe WORD bit is used to automatically route bytes of data onto the correct byte lanes enabling memorieswider than 8 bits to be fully utilized. On TM4C129x devices, the data is automatically routed, meaning thebit is no longer necessary. The RD2CYC bit is required to be set on LM3S devices, so it was removed andall reads in General-Purpose mode are 2 cycles. As a result of these changes, the followingAPI/parameter combinations should not be used:• EPI_HB8_WORD_ACCESS with EPIConfigHB8Set()• EPI_HB16_WORD_ACCESS with EPIConfigHB16Set()• EPI_GPMODE_WORD_ACCESS with EPIConfigGPModeSet()• EPI_GPMODE_READ2CYCLE with EPIConfigGPModeSet()• EPI_GPMODE_RDYEN with EPIConfigGPModeSet()• EPI_HB8_MODE_SRAM and EPI_HB8_CSCFG_ALE_DUAL_CS or EPI_HB8_CSCFG_DUAL_CSwith EPIConfigHB8Set()• EPI_HB16_MODE_SRAM and EPI_HB16_CSCFG_ALE_DUAL_CS or EPI_HB16_CSCFG_DUAL_CSwith EPIConfigHB16Set()13 G
EPI没有用过，上面这段话是从从LM3S系列到TIVA C系列的过度这本书上找到的。你可以参考看看。
