MCF5329DS ANALOGICTECH [Advanced Analogic Technologies], MCF5329DS Datasheet - Page 23

• Manufacturer Part Number: MCF5329DS
• Description: MCF5329 ColdFire Microprocessor Data Sheet
• Manufacturer: ANALOGICTECH [Advanced Analogic Technologies]

5.7.1
A multi-function external bus interface called FlexBus is provided with basic functionality to interface to
slave-only devices up to a maximum bus frequency of 80MHz. It can be directly connected to
asynchronous or synchronous devices such as external boot ROMs, flash memories, gate-array logic, or
other simple target (slave) devices with little or no additional circuitry. For asynchronous devices a simple
chip-select based interface can be used. The FlexBus interface has six general purpose chip-selects
(FB_CS[5:0]) which can be configured to be distributed between the FlexBus or SDRAM memory
interfaces. Chip-select, FB_CS0 can be dedicated to boot ROM access and can be programmed to be byte
(8 bits), word (16 bits), or longword (32 bits) wide. Control signal timing is compatible with common
ROM/flash memories.
5.7.1.1
The following timing numbers indicate when data will be latched or driven onto the external bus, relative
to the system clock.
Freescale Semiconductor
* The timings are also valid for inputs sampled on the negative clock edge.
FB_CLK
FlexBus
FlexBus AC Timing Characteristics
Inputs
Input Setup And Hold
FB_CLK (80MHz)
Input Rise Time
Input Fall Time
MCF5329 ColdFire
B4
Figure 9. General Input Timing Requirements
Invalid
®
Microprocessor Data Sheet, Rev. 0.1
V
V
Preliminary
V
V
h
h
l
l
= V
= V
= V
= V
IH
IH
TSETUP
IL
IL
1.5V
Valid
1.5V
THOLD
1.5V
t
t
rise
fall
Invalid
Preliminary Electrical Characteristics
B5
23