Lattice XO2内部RAM使用手册.pdfVIP

1 rd1126_01.1 June 2012 Reference Design RD1126 ? 2012 Lattice Semiconductor Corp. All Lattice trademarks, registered trademarks, patents, and disclaimers are as listed at /legal. All other brand or product names are trademarks or registered trademarks of their respective holders. The specifications and information herein are subject to change without notice. Introduction MachXO2?-640/U and higher density devices provide a User Flash Memory (UFM) block, which can be used for a variety of applications including PROM data storage, or general purpose non-volatile Flash memory. In some design contexts, the UFM may be used concurrently to store EFB initialization data, or in rare situations configura- tion data overflow, as specified by user settings. The UFM is page addressable. Each page has 128 bits (16 bytes). The UFM block connects to the device core through the Embedded Function Block (EFB) WISHBONE interface. If desired, users can also access the UFM block independently through the hardened JTAG, I2C and SPI interfaces of the device. This reference design is intended to provide a familiar and intuitive extension to the MachXO2 Embedded Func- tional Block User Flash Memory (EFB UFM). This design facilitates users to access the MachXO2 EFB UFM mod- ule without the knowledge of WISHBONE protocol. Architecture Figure 1. MachXO2 UFM Simplified RAM-Type Interface Block Diagram RD1126 WISHBONE Interface MEM_CLK SM_CLK MEM_WE SM_WE SM_CEMEM_CE Internal State Machine UFM MEM_ Rd_DATA [7:0] DPRAM P o rt A P o rt B SM_Rd_DATA [7:0] SM_Wr_DATA [7:0] SM_ADDR [4:0] ]0:7[ ATAD_rW_MEM ]0:3[ RDDA_MEM ~SM_ADDR [4] Instruction Decoder E R R B U S Y C M D [2 :0 ] U F M _P A G E [1 0: 0] G O R S T _N C LK MachXO2 RAM-Type Interface for Embedded User Flash Memory 2RAM-Type Interfa