Re: 3D ROM

On Mar 28, 12:05 pm, Herbert Kleebauer <k...@xxxxxxxxx> wrote:
kaja_love...@xxxxxxxxx wrote:
On Mar 28, 8:07 am, Herbert Kleebauer <k...@xxxxxxxxx> wrote:
kaja_love...@xxxxxxxxx wrote:
, hoping that perhaps someone will find the time and patience to look
at the file and help me understand what is going on. If there is a
better way to post this file, please tell.

A static RAM has three types of connections:

- n address lines A(n-1).....A0
The binary number on this lines addresses one of 2^n memory locations

- m data lines D(m-1)....D0
Transfers data from and to a memory location. Some SRAMS have separate
data lines for input ( D(m-1)....D0 ) and output ( Q(m-1)...Q0 ).

- control lines
CS~: chip select: if 0, the SRAM is selected if 1, the SRAM in inactive (data
out is high impedance)
RW~: read/write: if 0 write access, if 1 read access
OE~: output enable: if 0, data out active, if 1 data out high impedance

In your example there seems to be no active low but active high control
signals for CS and RW, so the meaning of 0<->1 is reversed. It also
seems to be a SRAM with separate in- and output D/Q.

* No, Q definitelly means quit ( it said quit in original file, I just
abbreviated it )

A SRAM doesn't have a "Quit". Are you sure it wasn't labled "Qout"?

* One of the questions was:

"At time T(16) = 10 the RAM's output value is ......."

This doesn't make any sense when D also is the output because
then you only have to use the value at T=0x10 from the D line
of the table (0xB).

At time T = 10, WE equals 1, which means that value ' D ' should be
written into memory location ' 0 '. But question asks what the output
value is. If data is written into memory, then there shouldn't be an
output value, so isn't the above question kinda wrong?!

The table doesn't make a sense at all. If you write at T=2 a D=6 into
A=0 then you can't read a D=4 in the next cycle from the same memory
location. But you only can ask this questions to the author of exercise.



thank you

.

Relevant Pages

  • Re: 3D ROM
    ... Transfers data from and to a memory location. ... CS~: chip select: if 0, the SRAM is selected if 1, the SRAM in inactive (data ... OE~: output enable: if 0, data out active, if 1 data out high impedance ... No, Q definitelly means quit (it said quit in original file, I just ...
    (alt.lang.asm)
  • Re: 3D ROM
    ... Transfers data from and to a memory location. ... CS~: chip select: if 0, the SRAM is selected if 1, the SRAM in inactive (data ... OE~: output enable: if 0, data out active, if 1 data out high impedance ... No, Q definitelly means quit (it said quit in original file, I just ...
    (alt.lang.asm)