AN2148 Motorola / Freescale Semiconductor, AN2148 Datasheet - Page 8

• Manufacturer Part Number: AN2148
• Description: Design Considerations for Interfacing SDRAM with MC68VZ328
• Manufacturer: Motorola / Freescale Semiconductor

SDRAM Control Registers
3
This section will cover the relevant registers involved in SDRAM operations. The following registers have
an effect on SDRAM operation:
For certain registers, only a number of fields are of relevance to SDRAM operation. The table below lists
the relevant fields for each register.
3.1
When VZ is configured to use SDRAM, chip-select group D[1:0] are used for SDRAM chip-selects. At the
same time, chip-select group C[1:0] becomes the SDCAS and SDRAS signals. During this time, all
chip-select group C registers are ignored.
3.1.1
This register holds the base address for SDRAM. The value in this register represents A[28:14] of the
address bus. So a value of 0x0800 will put the SDRAM at 0x01000000.
8
CSD
CSCTRL1
CSCTRL2
DRAMC
Name
CSGBD
CSD
CSCTRL1
CSCTRL2
DRAMMC
DRAMC
SDCTRL
SDPWDN
SDRAM Control Registers
Chip-Select Registers
Chip-Select Group D Base Address Register (CSGBD)
Name
Design Considerations for Interfacing SDRAM with MC68VZ328
Chip-Select Register D
Chip-Select Control Register 1
Chip-Select Control Register 2
DRAM Control Register
0x(FF)FFF106
0x(FF)FFF116
0x(FF)FFF10A
0x(FF)FFF10C
0x(FF)FFFC00
0x(FF)FFFC02
0x(FF)FFFC04
0x(FF)FFFC06
Table 4. SDRAM Registers Relevant Fields
Address
Description
Table 3. SDRAM Registers
Pre-Publication Draft
Chip-Select Group D Base Address
Chip-Select Register D
Chip-Select Control Register 1
Chip-Select Control Register 2
DRAM Memory Configuration Reg.
DRAM Control Register
SDRAM Control Register
SDRAM Power-down Register
COMB, DRAM, BSW, WS3-1, SIZ, EN
DSIZ3
ECDD, ECDT
EN, RM, CLK, PGSZ, LSP, RST
Description
Relevant Fields
Table 6-5
Table 6-10
Table 6-12
Table 6-13
Table 7-6
Table 7-7
Table 7-8
Table 7-10
VZ Manual