mc68hc916y3 Freescale Semiconductor, Inc, mc68hc916y3 Datasheet - Page 39

• Manufacturer Part Number: mc68hc916y3
• Description: Mc68hc16y3 16 Bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

3.2 Intermodule Bus
3.3 System Block Diagram and Pin Assignment Diagrams
MC68HC16Y3/916Y3
USER’S MANUAL
The intermodule bus (IMB) is a standardized bus developed to facilitate the design of
modular microcontrollers. It contains circuitry that supports exception processing, ad-
dress space partitioning, multiple interrupt levels, and vectored interrupts. The stan-
dardized modules in MC68HC16Y3 and MC68HC916Y3 MCUs communicate with
one another and external components via the IMB. Although the full IMB supports 24
address and 16 data lines, MC68HC16Y3 and MC68HC916Y3 MCUs use only 20 ad-
dress lines. Because the CPU16 uses only 20 address lines. ADDR[23:20] follow the
state of ADDR19.
Figures 3-1 and 3-2 show functional block diagrams of MC68HC16Y3 and
MC68HC916Y3 MCUs. Although diagram blocks represent the relative size of the
physical modules, there is not a one-to-one correspondence between location and
size of blocks in the diagram and location and size of integrated-circuit modules.
Figures 3-3 and 3-4 show MC68HC16Y3 and MC68HC916Y3 pin assignments based
on a 160-pin plastic surface-mount package. Refer to APPENDIX B MECHANICAL
DATA AND ORDERING INFORMATION for information on how to obtain package
dimensions. Refer to subsequent paragraphs in this section for pin and signal
descriptions.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA
3-3