![Texas Instruments CC2533 Скачать руководство пользователя страница 23](http://html.mh-extra.com/html/texas-instruments/cc2533/cc2533_user-manual_1094592023.webp)
Overview
1.1.1 CPU and Memory
The 8051 CPU core is a single-cycle 8051-compatible core . It has three different memory access buses
(SFR, DATA, and CODE/XDATA) with single-cycle access to SFR, DATA, and the main SRAM. It also
includes a debug interface and an 18-input extended interrupt unit. The detailed functionality of the CPU
and the memory is addressed in
The interrupt controller services a total of 18 interrupt sources, divided into six interrupt groups, each of
which is associated with one of four interrupt priorities. Any interrupt service request is serviced also when
the device is in idle mode by going back to active mode. Some interrupts can also wake up the device
from sleep mode (when in sleep mode, the device is in one of the three low-power modes PM1, PM2, or
PM3); see
for more details.
The memory arbiter is at the heart of the system, as it connects the CPU and DMA controller with the
physical memories and all peripherals through the SFR bus. The memory arbiter has four memory access
points, access of which can map to one of three physical memories: SRAM, flash memory, and
XREG/SFR registers. It is responsible for performing arbitration and sequencing between simultaneous
memory accesses to the same physical memory.
The 4/6/8-KB SRAM maps to the DATA memory space and to parts of the XDATA memory spaces. The
SRAM is an ultralow-power SRAM that retains its contents in all power modes . This is an important
feature for low-power applications.
The 32/64/96/128/256 KB flash block provides in-circuit programmable non-volatile program memory for
the device, and maps into the CODE and XDATA memory spaces. In addition to holding program code
and constants, the non-volatile memory allows the application to save data that must be preserved such
that it is available after restarting the device. Using this feature one can, e.g., use saved network-specific
data to avoid the need for a full start-up and network find-and-join process.
1.1.2 Clocks and Power Management
The digital core and peripherals are powered by a 1.8-V low-dropout voltage regulator (
).
Additionally, the CC253x/CC2540/41 contains a power management functionality that allows the use of
different low-power modes (PM1, PM2, and PM3) for low-power applications with a long battery life (see
for more details). Five different reset sources exist to reset the device; see
for more
details.
1.1.3 Peripherals
The CC253x/CC2540/41 includes many different peripherals that allow the application designer to develop
advanced applications. Not all peripherals are present on all devices. See
for a listing of which
peripherals are present on each device.
The debug interface (
) implements a proprietary two-wire serial interface that is used for
in-circuit debugging. Through this debug interface, it is possible to perform an erasure of the entire flash
memory, control which oscillators are enabled, stop and start execution of the user program, execute
supplied instructions on the 8051 core, set code breakpoints, and single-step through instructions in the
code. Using these techniques, it is possible to perform in-circuit debugging and external flash
programming elegantly.
The device contains flash memory for storage of program code. The flash memory is programmable from
the user software and through the debug interface (as mentioned previously). The flash controller
(
) handles writing and erasing the embedded flash memory. The flash controller allows
page-wise erasure and 4-bytewise programming.
The I/O controller (
) is responsible for all general-purpose I/O pins. The CPU can configure
whether peripheral modules control certain pins or whether they are under software control, and if so,
whether each pin is configured as an input or output and if a pullup or pulldown resistor in the pad is
connected. CPU interrupts can be enabled on each pin individually. Each peripheral that connects to the
I/O pins can choose between two different I/O pin locations to ensure flexibility in various applications.
23
SWRU191C
–
April 2009
–
Revised January 2012
Introduction
Copyright
©
2009
–
2012, Texas Instruments Incorporated