ST90158-ST90135 Datasheet, PDF (83/190 Pages) STMicroelectronics – 8/16-BIT MCU FAMILY WITH UP TO 64K ROM/OTP/EPROM AND UP TO 2K RAM

ST90158 - EXTERNAL MEMORY INTERFACE (EXTMI)
EXTERNAL MEMORY SIGNALS (Cont’d)
Figure 44. Effects of DS2EN on the behavior of DS and DS2
n
NO WAIT CYCLE
T1
T2
1 DS WAIT CYCLE
T1
T2
SYSTEM
CLOCK
AS (MC=0)
DS STRETCH
DS2EN=0 OR (DS2EN=1 AND UPPER MEMORY ADDRESSED):
DS
(MC=0)
DS
(MC=1, READ)
DS
(MC=1, WRITE)
DS2
DS2EN=1 AND LOWER MEMORY ADDRESSED:
DS
DS2
(MC=0)
DS2
(MC=1, READ)
DS2
(MC=1, WRITE)
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