SST89V54RD2 Silicon Storage Technology, Inc., SST89V54RD2 Datasheet - Page 13

• Manufacturer Part Number: SST89V54RD2
• Description: Flashflex51 Mcu
• Manufacturer: Silicon Storage Technology, Inc.

FlashFlex MCU
SST89V54RD2/RD / SST89V58RD2/RD
read and write signals (P3.6 - WR# and P3.7 - RD#) for
external memory use. Table 3-3 shows external data mem-
ory RD#, WR# operation with EXTRAM bit.
TABLE
©2007 Silicon Storage Technology, Inc.
EXTRAM = 0
EXTRAM = 1
1. Access limited to ERAM address within 0 to 0FFH; cannot access 100H to 02FFH.
AUXR
3-3: External Data Memory RD#, WR# with EXTRAM bit
RD# / WR# not asserted
RD# / WR# asserted
ADDR < 0300H
MOVX @DPTR, A or MOVX A, @DPTR
RD# / WR# asserted
RD# / WR# asserted
ADDR >= 0300H
13
The stack pointer (SP) can be located anywhere within the
256 bytes of internal RAM (lower 128 bytes and upper 128
bytes). The stack pointer may not be located in any part of
the expanded RAM.
MOVX @Ri, A or MOVX A, @Ri
RD# / WR# not asserted
RD# / WR# asserted
ADDR = Any
S71255-10-000
Data Sheet
1
T3-3.0 1255
12/07