AN2408 Freescale Semiconductor / Motorola, AN2408 Datasheet - Page 22

• Manufacturer Part Number: AN2408
• Description: Examples of HCS12 External Bus Design A Companion Note to AN2287/D
• Manufacturer: Freescale Semiconductor / Motorola

Conclusion
The actual external access only requires about 20 cycles. If block transfers are implemented, the interface
will operate faster (about one-tenth the rated speed of low-cost 70 ns FLASH memory). This is
approximately equivalent to a 2.5 MB per second transfer rate.
Conclusion
Freescale Semiconductor’s HCS12 external bus enables the designer to create an expanded device
system for situations where a single-chip solution is impractical due to cost or availability of peripherals.
Using the HCS12 external bus to create an expanded device system means the designer can add to the
functions available on a single MCU.
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Examples of HCS12 External Bus Design, Rev. 2
Figure 19. Software Flash Interface
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Freescale Semiconductor
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