topic Re: SDRAM connections MCF5208 in ColdFire/68K Microcontrollers and Processors

SDRAM connections MCF5208

fevernova — Thu, 27 Sep 2007 17:32:05 GMT

Hi at all,

I will develop a board with the mcf5208.

Now I will know how to connect one or two (assembly option) respectively sdrams (K4S281632) to the cpu.

These signals are clear to me: -1st sdram D16-D31 to dq0-dq15

-dqm3 to udqm

-dqm2 to ldqm

-2nd sdram D0-D15 to dq0-dq15

-dqm1 to udqm

-dqm0 to ldqm

And what's about the address lines and chip selects?

Same address lines in 16bit and 32bit?

One chip select for both modes (16/32bit) or two?

thx

fevernova

Re: SDRAM connections MCF5208

UK_CF_FAE — Mon, 08 Oct 2007 22:40:26 GMT

Hello FeverNova,

I diodn't look up those memory chips. I guess that they are by-16 architecture. Since the ColdFire has byte addressability, then you need to connect the A0 from the mcu to the A1 on the memory, etc. From your description of what you know already, you seem to want to make a 32-bit wide memory from the 2-off x16 parts, that's why you'd connect the D16 to dq0 on the first sdram. Then you say its a assembly option, which puzzled me.

2 references for you to look at:

1) Schematic for the MCF5208 eval board, published to the freescale site

2) FlexBus application note AN2982.

Good luck

Mark

Re: SDRAM connections MCF5208

fevernova — Tue, 09 Oct 2007 13:45:07 GMT

...let's start new.

I will use sdram by 16bit architecture (k4s281632I-ui75) and flash (s29gl032a90tfir4) by 16bit architecture.

So I'll take a full 32bit bus mode for 32bit sdram controller and 32bit for flexbus (dramsel=1).

As standard memory I will use one 16bit sdram and so I thought I have to connect the sdram to the upper data lines of the sdram controller:

sdram dq0=cpu d16

sdram dq1=cpu d17

...

sdram dq15=cpu d31

sdram ldqm=cpu sddqm2

sdram udqm=cpu sddqm3

sdram cs=cpu sdcs0

sdram a0=cpu a0

sdram a1=cpu a1

...

sdram a10=cpu sd_a10

...

sdram n.c./a12=cpu a12

sdram ba0=cpu a14

sdram ba1=cpu a15

And here isthe flash connection:

flash a0=cpu a1

flash a1=cpu a2

...

flash n.c./a21=cpu a22

flash cs=cpu cs0

flash dq0=cpu d16

flash dq1=cpu d17

...

flash dq15=cpu d31

refer to page 287 (flexbus, data byte alignment) in manual.

A an assembly option I will use a second sdram by 16bit to built a 32bit architecture by 2x16bit.

So I take the second sdram and connect it in this way:

sdram dq0=cpu d0

sdram dq1=cpu d1

...

sdram dq15=cpu d15

sdram ldqm=cpu sddqm0

sdram udqm=cpu sddqm1

sdram cs=cpu sdcs0

sdram a0=cpu a0

sdram a1=cpu a1

...

sdram a10=cpu sd_a10

...

sdram n.c./a12=cpu a12

sdram ba0=cpu a14

sdram ba1=cpu a15

Is it the correct connection?

I hope it is understandable.

thx, fevernova

Re: SDRAM connections MCF5208

fevernova — Tue, 23 Oct 2007 19:12:50 GMT

Does anybody has an idea?

best regards...René

Re: SDRAM connections MCF5208

Maybar — Tue, 04 Dec 2007 00:54:35 GMT

Did you resolve the problem?
I have the same question:
Coldfire 5208 in 32 bit mode.
Flash and SDR RAM with 16 bit size.
Is correct to connect cpu(A1-A21) to Flash[A0-A20]?
Thanks,
Miguel.

Re: SDRAM connections MCF5208

fevernova — Tue, 04 Dec 2007 15:12:29 GMT

I think so. Refer to 17.3.1.1 Port Sizing in Manual.

Bye