9-8
MCF5272 User’s Manual
SDRAM Registers
Table 9-7. SDCR Field Descriptions
Bits
Name
Description
15
—
Reserved, should be cleared.
14–13
MCAS
Maximum CAS address. Determines which device address output carries the column address
msb. For example, if the SDRAM device has eight column addresses and the data bus is
configured for 32 bits, the column address appears on A[9:2], so the maximum column address is
A9. The lsb of the row address is therefore taken from internal address signal A10 and is used by
the SDRAM controller to control address multiplexing.
00 A7
01 A8
10 A9
11 A10
12–11
—
Reserved, should be cleared.
10–8
BALOC Bank address location. Determines the internal addresses that become SDRAM bank addresses.
SDBA1
SDBA0
000
Reserved
001
A21
A20
010
A22
A21
011
A23
A22
100
A24
A23
101
A25
A24
110
Reserved
111
Reserved
7
GSL
Go to sleep. Setting GSL powers down the SDRAM and puts it into auto-refresh mode.
6–5
—
Reserved, should be cleared.
4
REG
Register read data for 66 MHz. Writing a 1 to REG enables pipeline mode for read data access. It
forces the SDRAM controller to register the read data, adding one wait state to single-read
accesses and to the first word read during a burst. REG must be 1 for clock frequencies above
48 MHz to meet input setup timing for data input (See electrical characteristics timing SD16). The
description of INV shows how REG and INV interact.
3
INV
Invert clock. Inverts SDRAM clock output for timing refinement.
If REG = 0
0 Do not add wait state for read accesses.
1 Shift SDCLK edge 180
o
If REG = 1
0 Add wait state for read accesses, all frequencies
1 Invalid, do not use.
2
SLEEP
SLEEP mode. This read-only status bit goes high when setting SDCR[GSL] has taken effect and
the SDRAM is powered down. SLEEP is cleared when SDRAM is in auto-refresh mode.
1
ACT
Active. This read-only status bit goes high when the SDRAM controller completes its initialization.
ACT is cleared by writing to SDCR.
0
INIT
Initialization enable. Setting INIT enables initialization of the SDRAM based on other SDCR bit
values. Initialization starts after the first dummy write access to the SDRAM. CSOR7, CSBR7, and
SDTR must be configured before setting INIT.
CAUTION: CSOR7[WAITST] must equal 0x1F when CS7/SDCS is configured for SDRAM.
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
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Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...