MFR4300_07 Datasheet, PDF (46/266 Pages) Freescale Semiconductor, Inc – FlexRay Communication Controllers

Device Overview
The output frequency of the CLKOUT signal is selected by the CLK_S[1:0] input pins, in accordance with
Table 2-5:
Table 2-5. CLKOUT Frequency Selection
Pin
CLK_S0
CLK_S1
0
0
1
0
0
1
1
1
CLKOUT Function
4 MHz output
10 MHz output
40 MHz output
Disabled (CLKOUT output is “0“)
NOTE
As the CLK_S[1:0] signals are multiplexed with DBG[2:3], CLKOUT
should be selected using pullup and pulldown resistors
2.6.2 External Host Interface Selection
The MFR4300 can be connected and controlled by two types of interface through the CC EBI. Two pins,
IF_SEL0 and IF_SEL1, are used to configure the interface type, in accordance with Table 2-6.
Table 2-6. Interface Selection
Pin
IF_SEL0
0
0
1
1
IF_SEL1
0
1
0
1
Interface
Reserved
HCS12 Synchronous Interface
Asynchronous Memory Interface
Asynchronous Memory Interface
CHI and Host
Interface Clock
CLK_CC
CLK_CC
CLK_CC
CHICLK_CC
The CC latches the values of the IF_SEL0 and IF_SEL1 signals, when it leaves an internal or external reset
state, and analyzes them in order to configure the interface for the type of external host. The CC does not
analyze them after it has left the reset state. For more information on the internal and external reset states,
see Chapter 6, “Clocks and Reset Generator (CRG)”.
NOTE
If the CC senses the Reserved mode on its IF_SEL pins (IF_SEL[1:0] = 00),
it stops all internal operations, does not perform or respond to any host
transactions, stays in the configuration mode, and does not integrate into the
communication process.
The following steps must be taken to select a correct external host interface
mode:
1.Set IF_SEL0, IF_SEL1 for either the AMI or the HCS12 synchronous mode.
MFR4300 Data Sheet, Rev. 3
46
Freescale Semiconductor