Chapter 23. Electrical Characteristics
23-13
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
Debug AC Timing Specifications
PRELIMINAR
Y
23.4.1 SDRAM Interface Timing Specifications
Table 23-10 lists SDRAM interface timings.
Figure 23-9 shows SDRAM timings listed in Table 23-10.
NOTE:
Above 48 MHz, the memory bus may need to be configured for
one wait state. It is the responsibility of the user to determine
the actual frequency at which to insert a wait state since this
depends on the access time of SRAM or SDRAM used in a
particular system implementation.
Wait states are inserted for SRAM accesses by programming
bits 6–2 of the chip select option registers.
A wait state is added for SDRAM read accesses by setting bit
4 of the SDRAM control register.
Table 23-10. SDRAM Interface Timing Specifications
Name
Characteristic
1
1
All timing references to SDCLK are given to its rising edge when bit 3 of the SDRAM control register is 0.
0–66 MHz
Unit
Min
Max
Control Inputs
SD1
SDCLK to address output A[22:0] valid
—
8.5
nS
SD2
SDCLK to address output A[22:0] invalid (output hold)
1
—
SD3
SDCLK to DQM[3:0] valid
—
9
nS
SD4
SDCLK to DQM[3:0] invalid (output hold)
2
—
SD5
SDCLK to data output (D[31:0]) valid (signal from driven or three-state)
—
8
nS
SD6
SDCLK to data output (D[31:0]) invalid (output hold)
1
—
SD7
SDCLK to CAS0, RAS0, SDBA[1:0], SDCLKE, SDRAMWE, valid
—
7
nS
SD8
SDCLK to CAS0, RAS0, SDBA[1:0], SDCLKE, SDRAMWE, invalid (output hold)
1
—
SD9
SDCLK to SDCS valid
—
8
nS
SD10
SDCLK to SDCS invalid (output hold)
1.5
—
SD11
SDCLK to A10_PRECHG valid
—
9.5
SD12
SDCLK to A10_PRECHG invalid (output hold)
2
—
SD13
SDCLK to data output (D[31:0]) high impedance
—
6
nS
SD14
Data input (D[31:0]) valid to SDCLK (setup) (pipeline mode, SDRAM control
register b4 = 1)
2.5
—
nS
SD15
Data input (D[31:0]) valid to SDCLK (setup) (straight-through mode, SDRAM
control register b4 = 0)
12
—
nS
SD16
SDCLK to data input (D[31:0]) invalid (hold)
0
—
nS
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Страница 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
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 ...