mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 467

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

MOTOROLA
20.6.2 Interface for FLASH/SRAM Devices without Byte
CSBRn[EBI] is 11 for FLASH/SRAM devices and for peripherals having 8-bit data bus
widths and no byte strobe inputs. These type of memory devices have separate pins for
write enable, chip select, and output enable. All chip selects support this EBI mode.
The key difference between EBI = 11 and EBI = 00 is that BS[3:0] can be directly
connected to the R/W inputs of the 8-bit wide SRAM devices and the R/W output from the
MCF5272 can be left unconnected.
The number of wait states required for the external memory or peripheral can be
programmed in CSORn[WS]. The external transfer acknowledge signal, TA, is provided to
allow off-chip control of wait states. External control of wait states is enabled when
CSORn[WS] is 0x1F.
SDCLK
A[22:0]
D[31:0]
OE
R/W
CSn
BS[3:0]
TA
Figure 20-10. Longword Read; EBI=11; 32-Bit Port; Internal Termination
Strobes
(H)
(H)
(H)
Chapter 20. Bus Operation
C1
C2
External Bus Interface Types
20-13