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3 sdram mode/extended mode register (sdmr), Sdram mode/extended mode register (sdmr) -19, Section 18.7.3, “sdram mode/extended – Freescale Semiconductor MCF5480 User Manual

Page 467: Mode register (sdmr)

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Memory Map/Register Definition

MCF548x Reference Manual, Rev. 3

Freescale Semiconductor

18-19

CS3CFG = 94000019 = 64M @ 0x9400 0000-0x97FF FFFF
CS4CFG = 8000001b = 256M @ 0x8000 0000-0x8FFF FFFF
CS5CFG = 00000000 = disable

This gives 400 Mbyte total memory, at 0x8000 0000-0x98FF FFFF

18.7.3

SDRAM Mode/Extended Mode Register (SDMR)

The SDMR, shown in

Figure 18-10

, is used to write to the mode and extended mode registers that

physically reside within in the SDRAM chips. These registers must be programmed during SDRAM

initialization. See

Section 18.5.2, “Power-Up Initialization

” for more information on the initialization

sequence.

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

R

BNKAD

AD

0

CMD

W

Reset

Uninitialized

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

R

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

W

Reset

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Reg

Addr

MBAR +0x0100

Figure 18-10. SDRAM Mode/Extended Mode Register (SDMR)

Table 18-10. SDMR Field Descriptions

Bits

Name Description

31–30

BNKAD

Bank address. Driven onto SDBA[1:0] along with a LMR/LEMR command. All SDRAM chip
selects are asserted simultaneously. SDCR[CKE

] must be set before attempting to

generate an LMR/LEMR command. The SDBA[1:0] value is used to select between LMR
and LEMR commands.
00 Load mode register command (LMR)
01 Load extended mode register command (LEMR)
10–11 Reserved

29–18

AD

Address. Driven onto SDADDR[11:0] along with an LMR/LEMR command. The AD value
is stored as the mode (or extended mode) register data.

17

Reserved. Should be cleared.

16

CMD

Command.
1 Generate an LMR/LEMR command
0 Do not generate any command

15–0

Reserved. Should be cleared.

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