NEC PD78P214 Manuale Utente

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Chapter 13   Local Bus Interface Function

Fig. 13-10 shows an example of connecting memories to the 

µPD78214.  In this example, a PROM, SRAM, and

mask-programmable ROM are connected to the 

µPD78214.  Addresses are assigned to these memories as follows:

• PROM (

µPD27C512D-15)

: 0000H-FCFFH (

µPD78213)

2000H-0FD7FH (

µPD78212)

4000H-FCFFH (

µPD78214)

FFD0H-FFDFH as an external SFR area

• RAM (

µPD43256AC-12)

: 10000H-17FFFH

• Mask-programmable ROM (

µPD23C4000A) : 80000H-FFFFFH

Since the 

µPD23C4000A mask-programmable ROM requires a long access time, insert one wait state by means

of the programmable wait function (See Section 13.4).

The circuit enclosed in dotted lines (74HC375) is required only when an in-circuit emulator is used.  When the
emulator is not used, remove the 74HC375, and connect Dn and Qn (n = 1 to 4), respectively.  If the emulator is used
without this circuit, malfunctions may occur.  (Usually, however, normal operation is possible because of the
delays introduced by the address decoder and other circuitry.)  When this circuit is not used, the 150-ns version,
the 

µPD43256AC-15, can be used as RAM in place of the µPD43256AC-12.