Figure 3.2.1C Ready Timing Chart - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

3.2 External Memory Access
(2) Ready function
When the RYE bit of the bus control signal selection register (EPCR) is set to '1,' a wait cycle is inserted
while an L level signal appears at the R36/RDY pin in the event of an access to an external area. Thus, the
access cycle can be extended.
P37/CLK
P33/WRHX
P32/WRLX
P31/RDX
P30/ALE
P27 to 20/A23 to 16
P17 to 10/AD15 to 08
P07 to 00/AD07 to 00
P36/RDY
P37/CLK
P33/WRHX
P32/WRLX
P31/RDX
P30/ALE
P27-20/A23-16
P17-10/AD15-08
P07-00/AD07-00
2
The F MC-16LX has two types of automatic ready functions for external memory. The automatic ready
function automatically inserts one to three wait cycles without an external circuit under the following condi-
tions. The function inserts the wait cycles when an access is made to a low-order address external area
located between addresses 002000
between addresses 800000
function is activated by setting the LMR1/LMR0 bits (low-order address external area) or the HMR1/HMR0
bits (high-order address external area) of ARSR. In addition, the F
matic ready function for external I/O. This automatic ready function automatically inserts one to three wait
cycles without an external circuit when an access is made to an external area located between addresses
0000C0 and 0000FF
H
by setting the IOR1/IOR0 bits of ARSR.
44 Chapter 3: Memory
Even-number address word read
Read address
Read
address
Read
address
RDY pin fetch
Even-number address word read
Write address
Write
address
Write
address
Write data

Figure 3.2.1c Ready timing chart

and 7FFFFF
H
and FFFFFF . This function extends the access cycle. The automatic ready
H H
. This function extends the access cycle. This automatic ready function is activated
H
Read data
Even-number address
word write
Read address
Read address
Cycle extended by automatic ready
or to a high-order address external area located
H
2
MC-16LX has another built-in auto-
Even-number address
word write
Write address
Write
address
Write
address
Write data
Read address
MB90580 Series