Freescale Semiconductor FlexRay MFR4310 - External Host Interface Selection; Table 2-6. Interface Selection

Device Overview
MFR4310 Reference Manual, Rev. 2
46 Freescale Semiconductor
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 MFR4310 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.
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 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
The internal pull devices on IF_SEL1 and IF_SEL0 are enabled only during
reset; they are disabled after the reset operation is complete.
NOTE
The following steps must be taken to select a correct external host interface
mode.
1. Set IF_SEL0, IF_SEL1 for MPC mode, HCS12 synchronous mode or AMI mode.
0 1 40 MHz output
1 1 Disabled (CLKOUT output is “0“)
1
This is the default clock frequency selection (i.e. if no external pull
resistors are connected to CLK_S0 and CLK_S1, the internal pulldown
resistors on these pins take effect).
Table 2-6. Interface Selection
Pin
Interface
CHI and Host
Interface Clock
CRSR.ECS
IF_SEL0 IF_SEL1
0 0 MPC Interface CHICLK_CC 1
0 1 HCS12 Synchronous Interface CLK_CC 0
1 0 Asynchronous Memory Interface
1
1
This is the default interface (i.e. if no external pull resistors are connected to IF_SEL0 and IF_SEL1, the
internal pullup on IF_SEL0 and the internal pulldown on IF_SEL1 take effect).
CLK_CC 0
1 1 Asynchronous Memory Interface CHICLK_CC 1
Table 2-5. CLKOUT Frequency Selection
Pin
CLKOUT Function
CLK_S0 CLK_S1