Command and ap during – Motorola MPC8260 User Manual

Page 325

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MOTOROLA

Chapter 10. Memory Controller

10-49

Part III. The Hardware Interface

Now, from the SDRAM device point of view, during an

ACTIVATE

command, its address

port should look like Table 10-22

.

Table 10-19 indicates that to multiplex A[6Ð17] over A[17Ð28], PSDMR[SDAM] must be
011 and, because the internal bank selects are multiplexed over A[15Ð16], PSDMR[BSMA]
must be 010 (only the lower two bank select lines are used).

Note that if the device is connected to the BNKSEL pins, the value of PSDMR[BSMA] has
no effect. In the above example, address lines [18Ð19] are output on BNKSEL1 and
BNKSEL0, accordingly.

During a

READ

/

WRITE

command, the address port should look like Table 10-23.

Because AP alternates with A[7] of the row lines, set PSDMR[SDA10] = 011. This outputs
A[7] on the SDA10 line during the

ACTIVATE

command and AP during

READ

/

WRITE

and

CBR commands.

Table 10-24 shows the register conÞguration. Not shown are PSRT and MPTPR, which
should be programmed according to the device refresh requirements:

Table 10-22. SDRAM Device Address Port during

ACTIVATE

Command

ТA[0Р14]У

A[15Ð16]

A[17Ð28]

A[29Р31]

С

Internal bank select (A[18Ð19])

Row (A[6Ð17])

n.c.

Table 10-23. SDRAM Device Address Port during

READ

/

WRITE

Command

ТA[0Р14]У

A[15Ð16]

A[17]

A[18]

A[19]

A[20Ð28]

A[29Р31]

С

Internal bank select

DonÕt care

AP

DonÕt care

Column

n.c.

Table 10-24. Register Settings (Page-Based Interleaving

Register

Settings

BRx

BA

Base address

PS

00 = 64-bit port size

DECC

00

WP

0

MS

010 = SDRAM-60x bus

EMEMC

0

ATOM

00

DR

0

V

1

ORx

AM

1111_1100_0000

LSDAM

00000

BPD

01

ROWST

0110

NUMR

011

PMSEL

0

IBID

0

PSDMR

PBI

1

RFEN

1

OP

000

SDAM

011

BSMA

010

SDA10

011

RFRC

from device data sheet

PRETOACT

from device data sheet

ACTTOROW

from device data sheet

BL

0

LDOTOPRE

from device data sheet

WRC

from device data sheet

EAMUX

0

BUFCMD

0

CL

from device data sheet

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