XC2287 / XC2286 / XC2285
XC2000 Family Derivatives
Preliminary
Functional Description
This common memory space includes 16 Mbytes and is arranged as 256 segments of
64 Kbytes each, where each segment consists of four data pages of 16 Kbytes each.
The entire memory space can be accessed byte wise or word wise. Portions of the
on-chip DPRAM and the register spaces (ESFR/SFR) have additionally been made
directly bit addressable.
The internal data memory areas and the Special Function Register areas (SFR and
ESFR) are mapped into segment 0, the system segment.
The Program Management Unit (PMU) handles all code fetches and, therefore, controls
accesses to the program memories, such as Flash memory and PSRAM.
The Data Management Unit (DMU) handles all data transfers and, therefore, controls
accesses to the DSRAM and the on-chip peripherals.
Both units (PMU and DMU) are connected via the high-speed system bus to exchange
data. This is required if operands are read from program memory, code or data is written
to the PSRAM, code is fetched from external memory, or data is read from or written to
external resources, including peripherals on the LXBus (such as USIC or MultiCAN). The
system bus allows concurrent two-way communication for maximum transfer
performance.
Up to 64 Kbytes of on-chip Program SRAM (PSRAM) are provided to store user code
or data. The PSRAM is accessed via the PMU and is therefore optimized for code
fetches. A section of the PSRAM with programmable size can be write-protected.
Note: The actual size of the PSRAM depends on the chosen derivative (see Table 1).
16 Kbytes of on-chip Data SRAM (DSRAM) are provided as a storage for general user
data. The DSRAM is accessed via a separate interface and is, therefore, optimized for
data accesses.
2 Kbytes of on-chip Dual-Port RAM (DPRAM) are provided as a storage for user
defined variables, for the system stack, general purpose register banks. A register bank
can consist of up to 16 word wide (R0 to R15) and/or byte wide (RL0, RH0, …, RL7, RH7)
so-called General Purpose Registers (GPRs).
The upper 256 bytes of the DPRAM are directly bit addressable. When used by a GPR,
any location in the DPRAM is bit addressable.
1 Kbyte of on-chip Stand-By SRAM (SBRAM) is provided as a storage for system-
relevant user data that must be preserved while the major part of the device is powered
down. The SBRAM is accessed via a specific interface and is powered via domain M.
Data Sheet
36
V0.91, 2007-02
Draft Version
INFINEON [ Infineon ]
