CHAPTER 6 BUS CONTROL
User’s Manual U14272EJ3V0UM
114
Figure 6-2. ROM Read Cycle and Access Parameters
(a) Ordinary ROM cycle
TClock
(internal)
ADD(21:0)
(output)
MEMRD#
(output)
DATA(15:0)
(read)
ROMCS(3:0)#
(output)
WROMA(3:0)
Valid
Valid
(b) PageROM cycle
WROMA(3:0)
ADD(2:0)
(output)
TClock
(internal)
ADD(21:3)
(output)
DATA(15:0)
(read)
ROMCS(3:0)#
(output)
WPROM(2:0)
Valid
Valid
Valid
Valid
Valid
Remarks 1. ROMCS(2:0)# signals are alternated with general-purpose I/O signals and are defined as
general-purpose inputs after RTC reset. Set GPMD2REG and GPMD3REG registers in the GIU
to use them as ROMCS(2:0)#.
2. A circle in the figure indicates the sampling timing.
Содержание VR4181 mPD30181
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