addr_out0..addr_out7 pin; ″address out, Port A pins
″Address output
WSIPSD PROPERTY ′Address_Out Aout[7:0]:addr_out
[7:0] PortA′;
addr_out8..addr_out15 pin; ″address out,Port B pins
″Address output
WSIPSD PROPERTY ′Address Out Aout 《15:8]:addr
out[15:8] PortB′
a16,a17,a18 pin 18,17,14; ″pc[2:4],a[16:18]
″Extend Address output
LCD_ce pin 11; ″pc7, the signal ce of LCD
SRAM_ce pin 9, ″pd1, the ce of 512K SRAM
ale pin 10; ″pin 10 address latch enable or PD0
csi pin 8; ″pin 8,/csi or pd2
fs7,fs6,fs5,fs4,fs3,fs2,fs1,fs0 node; ″Main Flash
segment chip selects
rs0 node;″PSD SRAM chip select
csiop node;″PSD control and I/O register
jtagsel node; ″Selects JTAG port active using a prod uct term
X = .x.; ″Don′t care symbol
address = [a18..a0]; ″De-muxed microcontroller
address signals
EQUATIONS
jtagsel = 0;
fs0 = (address >=^h2000 & address <=^h2FFF);
″Address of ROM
fs1 = (address >=^h3000)&(address <=^h3FFF);
fs2 = (address >=^h4000)&(address <=^h4FFF);
fs3 = (address >=^h5000)&(address <=^h5FFF);
fs4 = (address >=^h6000)& (address <=^h6FFF);
rs0 = (address >=^h7000)& (address <=^h77FF);
LCD_ce = (address >=^h7800) &(address <=^h7FFF);
csiop = (address >=^h8000) & (address <=^h80FF);
SRAM_ce=!(!a16&!a17&!a18)#((address >=^h8100 & (address <=^hFFFF)); ″Address
of RAM
end c51_813
由于PSD813具有很高的集成度和很强的在线编程功能,所以其应用对提高单片机的开发速度、系统稳定性及灵活性都比传统的设计方式有了很大的提高,这应该成为单片机应用系统的一个发展方向。
但PSD813内部数据总线为8位,所以虽然PSD813与8位MCU可以很方便地直接相连,但与16位单片机相连时,必须用两片PSD813以构成16位的多路复用和非多路复用总线结构接口。并且由于16位单片机与外部存储器的连接规则,所以当两片PSD813与16位单片机相连时,其地址线连接必须循环移位一次,以保证CPU在工作时同时正确接收两片PSD813 ROM中的高位和低位指令字节。
,PSD813器件在单片机系统中应用