UPSD33XX Datasheet, PDF (15/231 Pages) STMicroelectronics – Fast 8032 MCU with Programmable Logic

uPSD33xx
MEMORY ORGANIZATION
The 8032 MCU core views memory on the MCU
module as “internal” memory and it views memory
on the PSD module as “external” memory, see
Figure 6.
Internal memory on the MCU Module consists of
DATA, IDATA, and SFRs. These standard 8032
memories reside in 384 bytes of SRAM located at
a fixed address space starting at address 0x0000.
External memory on the PSD Module consists of
four types: main Flash (64K, 128K, or 256K bytes),
a smaller secondary Flash (16K, or 32K), SRAM
(2K, 8K, or 32K bytes), and a block of PSD Module
control registers called CSIOP (256 bytes). These
external memories reside at programmable ad-
dress ranges, specified using the software tool
PSDsoft Express. See the PSD Module section of
this document for more details on these memories.
External memory is accessed by the 8032 in two
separate 64K byte address spaces. One address
space is for program memory and the other ad-
dress space is for data memory. Program memory
is accessed using the 8032 signal, PSEN. Data
memory is accessed using the 8032 signals, RD
and WR. If the 8032 needs to access more than
64K bytes of external program or data memory, it
must use paging (or banking) techniques provided
by the Page Register in the PSD Module.
Note: When referencing program and data mem-
ory spaces, it has nothing to do with 8032 internal
SRAM areas of DATA, IDATA, and SFR on the
MCU Module. Program and data memory spaces
only relate to the external memories on the PSD
Module.
External memory on the PSD Module can overlap
the internal SRAM memory on the MCU Module in
the same physical address range (starting at
0x0000) without interference because the 8032
core does not assert the RD or WR signals when
accessing internal SRAM.
Figure 6. uPSD33xx Memories
Internal SRAM on
MCU Module
External Memory on
PSD Module
Fixed
Addresses
384 Bytes SRAM
FF Indirect
Addressing
128 Bytes
IDATA
SFR
80 ^{128 Bytes}
Direct
Addressing
7F
128 Bytes
DATA
0
Direct or Indirect Addressing
Main
Flash
64KB,
128KB,
or
256KB
• External memories may be placed at virtually
any address using software tool PSDsoft Express.
• The SRAM and Flash memories may be placed
in 8032 Program Space or Data Space using
PSDsoft Express.
• Any memory in 8032 Data Space is XDATA.
Secondary
Flash
SRAM
16KB
or
32KB
2KB,
8KB,
or
32KB
CSIOP
256 Bytes
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