Motorola MCF5281, MCF5282 user manual Sdram Example Specifications, Clkout, SRAS, Scas Dramw

Models: MCF5282 MCF5281

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SDRAM Example

CLKOUT

A[31:0]

SRAS, SCAS

DRAMW

D[31:0]

SD_CS[1] or [0]

MRS

Figure 15-10. Mode Register Set (MRS) Command

15.3 SDRAM Example

This example interfaces a 512K x 32-bit x 4 bank SDRAM component to a MCF5282 operating at 40 MHz. Table 15-25lists design specifications for this example.

Table 15-25. SDRAM Example Specifications

Parameter

Specification

 

 

Speed grade (-8E)

40 MHz (25-ns period)

 

 

10 rows, 8 columns

 

 

 

Two bank-select lines to access four internal banks

 

 

 

ACTV-to-read/write delay (tRCD)

20 ns (min.)

Period between auto-refresh and ACTV command (tRC)

70 ns

ACTV command to precharge command (tRAS)

48 ns (min.)

Precharge command to ACTV command (tRP)

20 ns (min.)

Last data input to PALL command (tRWL)

1 bus clock (25 ns)

Auto-refresh period for 4096 rows (tREF)

64 mS

MOTOROLA

Chapter 15. Synchronous DRAM Controller Module

15-19

Page 333
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Motorola MCF5281, MCF5282 user manual Sdram Example Specifications, Clkout, SRAS, Scas Dramw, Parameter Specification