mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 276

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

Synchronous DRAM Controller Module
15.2.1
Table 15-2
15.2.2
The DRAM controller registers memory map is shown in
15.2.2.1 DRAM Control Register (DCR)
The DCR, shown in
15-4
SRAS
SCAS
DRAMW
SDRAM_CS[1:0
]
SCKE
BS[3:0]
IPSBAR
Signal
Offset
0x04C
0x040
0x044
0x048
0x050
0x054
DRAM Controller Signals
describes the behavior of DRAM signals in synchronous mode.
Memory Map for SDRAMC Registers
Synchronous row address strobe. Indicates a valid SDRAM row address is present and can be latched by
the SDRAM. SRAS should be connected to the corresponding SDRAM SRAS.
Synchronous column address strobe. Indicates a valid column address is present and can be latched by
the SDRAM. SCAS should be connected to the corresponding SDRAM SCAS.
DRAM read/write. Asserted for write operations and negated for read operations.
Row address strobe. Select each memory block of SDRAMs connected to the processor. One
SDRAM_CS signal selects one SDRAM block and connects to the corresponding CS signals.
Synchronous DRAM clock enable. Connected directly to the CKE (clock enable) signal of SDRAMs.
Enables and disables the clock internal to SDRAM. When CKE is low, memory can enter a power-down
mode in which operations are suspended or capable of entering self-refresh mode. SCKE functionality is
controlled by DCR[COC]. For designs using external multiplexing, setting COC allows SCKE to provide
command-bit functionality.
Column address strobe. BS[3:0] function as byte enables to the SDRAMs. They connect to the BS signals
(or mask qualifiers) of the SDRAMs.
DRAM control register (DCR) [p. 15-4]
Figure
[31:24]
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
Table 15-2. Synchronous DRAM Signal Connections
15-2, controls refresh logic.
Table 15-3. DRAM Controller Registers
DRAM address and control register 0 (DACR0) [p. 15-6]
DRAM address and control register 1 (DACR1) [p. 15-6]
DRAM mask register block 0 (DMR0) [p. 15-8]
DRAM mask register block 1 (DMR1) [p. 15-8]
[23:16]
Description
—
Table
15-3.
[15:8]
—
Freescale Semiconductor
[7:0]