ST10 STMICROELECTRONICS [STMicroelectronics], ST10 Datasheet - Page 11

• Manufacturer Part Number: ST10
• Description: 16-BIT MCU WITH 32K BYTE ROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

IV - MEMORY ORGANIZATION
The memory space
configured in a Von-Neumann architecture. Code
memory, data memory, registers and I/O ports are
organized within the same linear address space of
16M Byte.
The entire memory space can be accessed Byte-
wise or Wordwise. Particular portions of the
on-chip memory have additionally been made
directly bit addressable.
ROM : 32K Byte of on-chip ROM.
RAM : 2K Byte of on-chip internal RAM
(dual-port) is provided as a storage for data, sys-
tem stack, general purpose register banks and
code. The register bank can consist of up to 16
wordwide (R0 to R15) and/or Bytewide (RL0,
RH0,
XRAM : 2K Byte of on-chip extension RAM (sin-
gle port XRAM) is provided as a storage for data,
user stack and code.
The XRAM is connected to the internal XBUS and
is accessed like an external memory in 16-bit
demultiplexed bus-mode without waitstate or
read/write delay (80ns access at 25MHz CPU
clock). Byte and Word access is allowed.
The XRAM address range is 00’E000h -
00’E7FFh if the XRAM is enabled (XPEN bit 2 of
SYSCON register). As the XRAM appears like
external memory, it cannot be used for the
ST10C167’s system stack or register banks. The
, RL7, RH7) general purpose registers.
of the ST10C167
is
XRAM is not provided for single bit storage and
therefore is not bit addressable. If bit XRAMEN is
cleared, then any access in the address range
00’E000h - 00’E7FFh will be directed to external
memory interface, using the BUSCONx register
corresponding to address matching ADDRSELx
register.
SFR/ESFR : 1024 Byte (2 * 512 Byte) of address
space is reserved for the special function register
areas. SFRs are wordwide registers which are
used for controlling and monitoring functions of
the different on-chip units.
CAN : Address range 00’EF00h - 00’EFFFh is
reserved for the CAN Module access. The CAN is
enabled by setting XPEN bit 2 of the SYSCON
register. Accesses to the CAN Module use demul-
tiplexed addresses and a 16-bit data bus (Byte
accesses are possible). Two wait states give an
access time of 160ns at 25MHz CPU clock. No
tristate waitstate is used.
Note
In order to meet the needs of designs where more
memory is required than is provided on chip, up to
16M Byte of external RAM and/or ROM can be
connected to the microcontroller.
If the CAN module is used, Port 4 can not
be programmed to output all 8 segment
address lines. Thus, only 4 segment
address lines can be used, reducing the
external memory space to 5M Byte (1M
Byte per CS line).
ST10C167
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