The four general-purpose timers on the QUICC are functionally similar to the two general-purpose timers

found on the MC68302. However, they offer some minor enhancements, such as the internal cascading of

two timers to form a 32-bit timer. The QUICC also contains a periodic interval timer in the SIM60, bringing the

total to five on-chip timers.

Upgrading Designs from the MC68302

Since the QUICC is a next-generation MC68302, many designers currently using the MC68302 may wish to

use the QUICC in a follow-on design. The following paragraphs briefly discuss this endeavor in terms of

architectural approach, hardware issues, and software issues.

Architectural Approach

The QUICC is the logical extension of the MC68302, but the overall architecture and philosophy of the

MC68302 design remains intact in the QUICC. The QUICC keeps the best features of the MC68302, while

making the changes required to provide for the increased flexibility, integration, and performance requested

by customers. Because the CPM is probably the most difficult module to learn, anyone who has used the

MC68302 can easily become familiar with the QUICC since the CPM architectural approach remains intact.

The most significant architectural change made on the QUICC was the translation of the design into the

standard M68300 family IMB architecture, resulting in a faster CPU and different system integration features.

Although the features of the SIM60 do not exactly correspond to those of the MC68302 SIM, they are very

similar. The QUICC SIM60 combines the best MC68302 SIM features with the best MC68340 SIM features

for improved performance.

Because of the similarity of the QUICC SIM60 and CPU to other members of the M68300 family, such as the

MC68332 and the MC68340, previous users of these devices will be comfortable with these same features

on the QUICC.

Hardware Compatibility Issues

The following list summarizes the hardware differences between the MC68302 and the QUICC:

• Pinout—The pinout is not the same. The QUICC has 240 pins; the MC68302 has 132 pins.

• Package—Both devices offer PGA and PQFP packages. However, the QUICC

PQFP package has a 20-mil pitch; whereas, the MC68302 PQFP package has a

25-mil pitch.

• System Bus—The system bus signals now look like those of the MC68030 as opposed to those of the

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com