simulation when lpm_ram_dq is used

When lpm_ram_dq is used to create memory, the simulation provided by Quartus II doesn't work any more.

high impedance in vhdl

Although vhdl is case insensitive, when it comes to high impedance, "Z" must be used instead of "z".

microcomputer design

load: 1,3
-- load register 3 with the memory data whose address is stored in register 1.

store: 2,4
-- put the data stored in register 2 into the memory address stored in register 4.

brgtI: 1,7, 58
-- branch to memory 58 if data stored in register 1 is greater that register 7.