M5373EVB Freescale Semiconductor, M5373EVB Datasheet - Page 19

• Manufacturer Part Number: M5373EVB
• Description: KIT EVAL FOR MCF537X
• Manufacturer: Freescale Semiconductor
• Series: ColdFire®r
• Type: MPUr

Specifications of M5373EVB

• Contents: Module and Misc Hardware
• For Use With/related Products: MCF537x
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

5.6.1
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.
5.6.1.1
The following timing numbers indicate when data is 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.
Num
FB1
FB2
FB3
—
FlexBus
FlexBus AC Timing Characteristics
Frequency of Operation
Clock Period (FB_CLK)
Address, Data, and Control Output Valid (A[23:0], D[31:0],
FB_CS[5:0], R/W, TS, BE/BWE[3:0] and OE)
Address, Data, and Control Output Hold (A[23:0], D[31:0],
FB_CS[5:0], R/W, TS, BE/BWE[3:0], and OE)
FB_CLK
Inputs
Input Setup And Hold
FB_CLK (80MHz)
Input Rise Time
MCF537x ColdFire
Input Fall Time
Figure 6. General Input Timing Requirements
Table 9. FlexBus AC Timing Specifications
B4
Characteristic
®
Invalid
Microprocessor Data Sheet, Rev. 4
V
V
V
V
h
h
1
1, 2
l
l
= V
= V
= V
= V
TSETUP
IH
IH
IL
IL
1.5V Valid
THOLD
1.5V
1.5V
t
t
FBCK (
t
Symbol
FBCHDCV
FBCHDCI
f
t
t
sys/3
rise
fall
t
cyc)
Invalid
B5
12.5
Min
—
—
1
Electrical Characteristics
Max
7.0
80
—
—
Unit
Mhz
ns
ns
ns
19