AN2417 Freescale Semiconductor / Motorola, AN2417 Datasheet - Page 2

• Manufacturer Part Number: AN2417
• Description: PCMCIA and Compact Flash Interface for the MC9328MX1 and MC9328MXL Application Processors Application Note
• Manufacturer: Freescale Semiconductor / Motorola

Introduction
1.2 Compact Flash Overview
Compact Flash is a PCMCIA compatible small removable 16 bit storage device introduced in 1994 by
SanDisk Corporation. Compact Flash cards are designed with flash technology, a non-volatile storage
solution that does not require a battery to retain data indefinitely. CF I/O cards are available as modems,
Ethernet, serial, BlueTooth wireless, 802.11b WiFi LAN, etc. Compared to a 68-pin PCMCIA PC Card, a
CF card has 50 pins and 11 bit address space, but still conforms to PCMCIA specifications.
Besides memory mode and I/O mode, Compact Flash can also operate in True IDE mode for easy interface
to hardware platforms containing IDE controllers.
Compact Flash is electrically compatible with PCMCIA specification.
1.3 Hardware Interface
This section describes the hardware interface between the PCMCIA / Compact Flash interface and the
MC9328MX1 ADS.
The PCMCIA / Compact Flash interface should be connected to MC9328MX1/MXL processor through
Chip Select 5 of EIM. The DTACK feature of CS5 allow PC Card / Compact Flash to use WAIT# signal to
extend normal access timing. As DTACK feature is available in Chip Select 5 only, the PCMCIA /
Compact Flash interface should not be connect to Chip Select other than CS5 unless programmable wait
state is used instead of DTACK.
The DragonBall MX processor cannot generate PCMCIA / CF bus cycle directly. For this reason, glue
logic is added between the PCMCIA / CF interface and the EIM interface to convert the signal from EIM
to the necessary PCMCIA / Compact Flash control signal. The glue logic also generate the right timing of
the control signal between the processor and the Compact Flash device, ensuring setup time and hold time
requirement of both devices are met.
The DragonBall MX processor will generate memory cycle that do not contain separated I/O control
signal. However the Compact Flash standard specify that separate read and write control signals be used to
distinguish between Compact Flash memory and I/O cycle. For this reason, address line A23 is used to
break the read and write control signal into memory and I/O cycle.
The address bus and data bus of Compact Flash interface is isolated from the processor address bus and
data bus by buffers. This is necessary to ensure the PCMCIA / Compact Flash device will not deteriorate
the bus during hot insertion / removal.
Compact Flash interface can work in three separate mode
Only Memory mode and I/O mode is support as this two operating mode is supported by all compact flash
device and is electrically compatible with PCMCIA
2
1. Memory mode
2. I/O mode
3. True IDE mode
Freescale Semiconductor, Inc.
For More Information On This Product,
MC9328MX1/MXL Application Note
Engineering Draft / Preliminary
Go to: www.freescale.com
MOTOROLA