mcf51em256 Freescale Semiconductor, Inc, mcf51em256 Datasheet - Page 41

• Manufacturer Part Number: mcf51em256
• Description: Microcontrollers Covers Mcf51em256 Mcf51em128
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor
1
2
3
Num
The performance of SPI2 depends on the configuration of power supply of the LCD pins. When the LCD pins
are configured with full complementary drive enabled (FCDEN = 1, VSUPPLY = 11 and RVEN = 0), and VLL3
is driven with external VDD, the SPI2 can operate at the max performance as the above table. When the internal
LCD charge pump is used to power the LCD pins, the SPI2 is configured with open-drain outputs. Its
performance depends on the value of the external pullup resistor implemented, and the max operating
frequency must be limited to 1 MHz.
SPI3 has open-drain outputs and its performance depends on the value of the external pullup resistor
implemented.
Refer to
10
11
12
13
1
2
3
4
5
6
7
8
9
3
Figure 19
C
D
D
D
D
D
D
D
D
D
D
D
D
D
Operating frequency
SPSCK period
Enable lead time
Enable lag time
Clock (SPSCK) high or low time
Data setup time (inputs)
Data hold time (inputs)
Slave access time
Slave MISO disable time
Data valid (after SPSCK edge)
Data hold time (outputs)
Rise time
Fall time
through
MCF51EM256 Series ColdFire Microcontroller Data Sheet, Rev.3
Characteristic
Figure
Preliminary—Subject to Change Without Notice
Table 22. SPI Electrical Characteristic
5
22.
6
4
Master
Master
Master
Master
Master
Master
Master
Master
Master
Output
Output
Slave
Slave
Slave
Slave
Slave
Slave
Slave
Slave
Slave
Input
Input
t
Symbol
WSPSCK
t
SPSCK
t
t
Lead
t
t
t
t
f
t
t
Lag
t
t
HO
RO
FO
t
dis
t
op
SI
HI
RI
FI
a
v
f
t
Bus
cyc
Min
1/2
1/2
—
—
15
15
25
—
—
—
—
—
—
—
—
/2048
0
2
4
0
0
0
– 30
1,2
1024 t
t
t
cyc
cyc
f
f
2048
—25
—25
Bus
Bus
Max
25
25
—
—
—
—
—
—
—
—
—
—
—
—
1
1
– 25
– 25
/2
/4
Electrical Characteristics
cyc
t
t
SPSCK
SPSCK
Unit
t
t
t
t
t
Hz
ns
ns
ns
ns
ns
ns
ns
cyc
cyc
cyc
cyc
cyc
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