mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 502

• Manufacturer Part Number: mcf5272
• Description: Mcf5272 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

AC Electrical Specifications
Read/write SRAM bus timings listed in Table 23-8 are shown in Figure 23-3, Figure 23-4,
Figure 23-5, and Figure 23-6.
1
2
23-8
B6a
B6b
B6c
B6d
B6e
B7a
B7b
B7c
B8
B9
B11
B12
B13
Name
All timing references to SDCLK are given to its rising edge when bit 3 of the SDRAM control register is 0.
Data output is held valid for one CPU clock period after deassertion of BS[3:0]
2
SDCLK to chip selects (CS[6:0]) valid
SDCLK to byte enables (BS[3:0]) valid
SDCLK to output enable (OE) valid
SDCLK to write enable (R/W) valid
SDCLK to reset output (RSTO) valid
SDCLK to control output (CS[6:0], OE) invalid (output hold)
SDCLK to control output (BS[3:0], R/W) invalid (output hold)
SDCLK to reset output (RSTO) invalid (output hold)
SDCLK to address (A[22:0]) valid
SDCLK to address (A[22:0]) invalid (output hold)
SDCLK to data output (D[31:0]) valid
SDCLK to data output (D[31:0]) invalid (output hold)
SDCLK to data output (D[31:0]) high impedance
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 23-8. Processor Bus Output Timing Specifications
Characteristic
Address and Attribute Outputs
MCF5272 User’s Manual
Control Outputs
Data Outputs
NOTE:
1
Min
1.5
1.0
1.5
—
—
—
—
—
—
—
—
4
1
0–66 MHz
Max
13.5
13.0
9.5
9.0
12
—
—
—
—
11
—
8
6
MOTOROLA
Unit
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS