您好,想请问vc33外扩ram的问题
vc33在mc方式下时,内部1000h到7fffffh是片内BOOT1和BOOT2区域,如果到外扩ram,则External (STRB Active),我把外扩RAM 定在480000h到4FFFFFh之间,片选信号和读写信号用lattice的LC4128完成。
RAM_CS1 <=((not A23) and A22 and (not A21) and (not A20) and A19 ); --程序RAM;
RAM_OE <= DSP_STRB or (not RW); --RAM读写信号;
RAM_WE <= DSP_STRB or RW;
cmd:
MEMORY
{
ERAM : o = 480000h, l = 3000h
RAM1: o = 809800h, l = 800h
}
SECTIONS
{
.text:> ERAM
.data:> ERAM
.bss :> ERAM
.cinit:> ERAM
.stack:> RAM1
.const:> ERAM
}