24-4
MC9328MX1 Reference Manual
MOTOROLA
SDRAM Memory Controller
24.3.7 Powerdown Timer
The powerdown timer detects periods of inactivity to the SDRAM and disables the clock when the inactive
period surpasses the selected time-out. Data is retained during the powerdown state. Subsequent requests
to the SDRAM incur only a minimal added start-up delay (beyond the normal access time). The
powerdown timer may be programmed to expire anytime the controller is not actively reading or writing
the memory, after 64 or 128 clocks of inactivity, or may be disabled entirely.
24.3.8 DMA Operation with the SDRAM Controller
The DMA controller has the capability to perform burst reads of byte and half word data types and the
SDRAM controller support is restricted to burst reads of word (32-bit) data types. Therefore, when using
the DMA in conjunction with the SDRAM controller, ensure that all burst reads from the SDRAM
controller are of word data types. This is configured in the DMA Channel Control Register. When
choosing SDRAM memory as the source address, set the Source Size Bits as a 32-bit port. Refer to the
Chapter 13, “DMA Controller,” for more details.
24.4 External Interface
This section discusses input and output signals between the SDRAM Controller and the external memory
devices. Other than the chip-select outputs (CSD0 / CSD1) and clock enables (SDCKE0 / SDCKE1), all
signals are shared between the two chip-select regions. The interface signals are summarized in Table 24-2
and detailed in Section 24.4.1 through Section 24.4.11. Interconnect and timing diagrams are included as
part of the detailed discussion on controller operation in Section 24.6, “Operating Modes.”
All external interface signals are referenced to the SDRAM clock, SDCLK.
Table 24-1. AHB Bus and Internal Interface Signals
Name
Function
Direction
clk32
32.0 kHz Clock Reference
Input
sf_wack
WMIMI bus time-out suppression for SyncFlash low-power mode
wake-up
Output
DQ [31:0]
Internal data I/O bus
I/O
Table 24-2. SDRAM Interface Pin Characteristics
SDRAMC
Signal
Name
MC9328MX1
Pin Name
Function
Direction
Reset State
SDCLK
SDCLK
Clock to SDRAM
Output
Enabled
SDCKE0
SDCLKE0
Clock enable to SDRAM 0
Output
High
SDCKE1
SDCLKE1
Clock enable to SDRAM 1
Output
High
CSD0
CS2
Chip-select to SDRAM array 0
Output
High
CSD1
CS3
Chip-select to SDRAM array 1
Output
High
MA [11:10]
MA [11:10]
Multiplexed Address
Output
Low
Summary of Contents for DragonBall MC9328MX1
Page 68: ...1 12 MC9328MX1 Reference Manual MOTOROLA Introduction ...
Page 86: ...2 18 MC9328MX1 Reference Manual MOTOROLA Signal Descriptions and Pin Assignments ...
Page 116: ...3 30 MC9328MX1 Reference Manual MOTOROLA Memory Map ...
Page 126: ...4 10 MC9328MX1 Reference Manual MOTOROLA ARM920T Processor ...
Page 160: ...8 8 MC9328MX1 Reference Manual MOTOROLA System Control ...
Page 272: ...13 32 MC9328MX1 Reference Manual MOTOROLA DMA Controller ...
Page 281: ...Programming Model MOTOROLA Watchdog Timer Module 14 9 ...
Page 282: ...14 10 MC9328MX1 Reference Manual MOTOROLA Watchdog Timer Module ...
Page 300: ...15 18 MC9328MX1 Reference Manual MOTOROLA Analog Signal Processor ASP ...
Page 438: ...18 16 MC9328MX1 Reference Manual MOTOROLA Serial Peripheral Interface Modules SPI 1 and SPI 2 ...
Page 478: ...19 40 MC9328MX1 Reference Manual MOTOROLA LCD Controller ...
Page 574: ...21 32 MC9328MX1 Reference Manual MOTOROLA Memory Stick Host Controller MSHC Module ...
Page 598: ...23 16 MC9328MX1 Reference Manual MOTOROLA Real Time Clock RTC ...
Page 670: ...24 72 MC9328MX1 Reference Manual MOTOROLA SDRAM Memory Controller ...
Page 726: ...25 56 MC9328MX1 Reference Manual MOTOROLA SmartCard Interface Module SIM ...
Page 736: ...26 10 MC9328MX1 Reference Manual MOTOROLA General Purpose Timers ...
Page 854: ...29 18 MC9328MX1 Reference Manual MOTOROLA I2C Module ...
Page 900: ...30 46 MC9328MX1 Reference Manual MOTOROLA Synchronous Serial Interface SSI ...
Page 942: ...32 26 MC9328MX1 Reference Manual MOTOROLA GPIO Module and I O Multiplexer IOMUX ...