
Signal Descriptions
MFR4200 Data Sheet, Rev. 0
Freescale Semiconductor
37
A[7:9] are AMI interface address signals.
ACS[0:2] are HCS12 interface address select signals.
2.2.3.3
OE#/ACS3 — AMI Read Output Enable, HCS12 Address Select Input.
OE#/ACS3 is a general purpose input pin. Its function is selected by the IF_SEL[0:1] pins. Refer to
Section 3.7, “Host Controller Interfaces
” for more information. The pin can be configured to enable or
disable either a pullup or pulldown resistor on the pin.
OE# is the AMI interface output enable signal. This signal controls MFR4200 data output and the state of
three-stated data pins D[15:0] during host read operations.
ACS3 is an HCS12 interface address select signal.
2.2.3.4
ACS[4:5] — HCS12 Address Select Inputs
ACS[4:5] are general purpose input pins.Their function is selected by the IF_SEL[0:1] pins. Refer to
Section 3.7, “Host Controller Interfaces
” for more information. The pins can be configured to enable or
disable either pullup or pulldown resistors on the pins.
ACS[4:5] are HCS12 interface address select signals. ACS5 is the MSB of the address select inputs.
2.2.3.5
D[15:0]/PAD[0:15] — AMI Data Bus, HCS12 Multiplexed Address/Data
Bus
D[15:0]/PAD[0:15] are general purpose input or output pins. Their functions are selected by the
IF_SEL[0:1] pins. Refer to
Section 3.7, “Host Controller Interfaces
” for more information. These pins can
be configured to provide either high or reduced output drive, and also to enable or disable either pullup or
pulldown resistors on the pins.
D[15:0] are data signals of the AMI interface. D0 is the LSB of the AMI data bus.
PAD[0:15] are HCS12 interface multiplexed address/data signals in the HCS12 Host interface mode of
operation. PAD0 is the LSB of the HCS12 address/data bus.
2.2.3.6
CE#/LSTRB — AMI Chip Select, HCS12 Low-byte Strobe
The function of this pin is selected by IF_SEL[0:1] pins.
Section 3.7, “Host Controller Interfaces
” for more
information. The pin can be configured to enable or disable either a pullup or pulldown resistor on the pin.
CE# is an AMI interface transfer size input signal. It indicates the size of the requested data transfer in the
current bus cycle.
LSTRB is an HCS12 interface low-byte strobe input signal. It indicates the type of bus access.