AT91FR4042 ATMEL Corporation, AT91FR4042 Datasheet - Page 6

• Manufacturer Part Number: AT91FR4042
• Description: The AT91FR4042 Features 256K Bytes of On-chip SRAM, 512K Bytes of Flash, an External Bus Interface, a 3-channel Timer/Counter, 2 Usarts, a Watchdog Timer And Advanced Power-saving Features.
• Manufacturer: ATMEL Corporation

Architectural
Overview
Memories
Peripherals
System Peripherals
6
AT91FR4042
Preliminary
The AT91FR4042 integrates Atmel’s AT91R40008 ARM Thumb processor and an
AT49BV4096A 4-Mbit Flash memory die in a single compact 121-ball BGA package.
The address, data and control signals, except the Flash memory enable, are internally
interconnected.
The AT91R40008 architecture consists of two main buses, the Advanced System Bus
(ASB) and the Advanced Peripheral Bus (APB). Designed for maximum performance
and controlled by the memory controller, the ASB interfaces the ARM7TDMI processor
with the on-chip 32-bit SRAM memory, the External Bus Interface (EBI) connected to
the encapsulated Flash and the AMBA
which is designed for accesses to on-chip peripherals and optimized for low power
consumption.
The AT91FR4042 implements the ICE port of the ARM7TDMI processor on dedicated
pins, offering a complete, low-cost and easy-to-use debug solution for target debugging.
The AT91FR4042 embeds 256K bytes of internal SRAM. The internal memory is
directly connected to the 32-bit data bus and is single-cycle accessible. This provides
maximum performance of 63 MIPS at 70 MHz by using the ARM instruction set of the
processor, minimizing system power consumption and improving on the performance of
separate memory solutions.
The AT91FR4042 features an External Bus Interface (EBI), which enables connection of
external memories and application-specific peripherals. The EBI supports 8- or 16-bit
devices and can use two 8-bit devices to emulate a single 16-bit device. The EBI imple-
ments the early read protocol, enabling faster memory accesses than standard memory
interfaces.
The AT91FR4042 encapsulates a Flash memory organized as 256K 16-bit words,
accessed via the EBI. A 16-bit Thumb instruction can be loaded from Flash memory in a
single access. Separate MCU and Flash memory reset inputs (NRST and NRSTF) are
provided for maximum flexibility. The user is thus free to tailor the reset operation to the
application.
The AT91FR4042 integrates resident boot software called AT91 Flash Uploader soft-
ware in the encapsulated Flash. The AT91 Flash Uploader software is able to upload
program application software into its Flash memory.
The AT91FR4042 integrates several peripherals, which are classified as system or user
peripherals.
All on-chip peripherals are 32-bit accessible by the AMBA Bridge, and can be pro-
grammed with a minimum number of instructions. The peripheral register set is
composed of control, mode, data, status and enable/disable/status registers.
An on-chip Peripheral Data Controller (PDC) transfers data between the on-chip
USARTs and on- and off-chip memory address space without processor intervention.
Most importantly, the PDC removes the processor interrupt handling overhead, making
it possible to transfer up to 64K contiguous bytes without reprogramming the start
address, thus increasing the performance of the microcontroller, and reducing the power
consumption.
The External Bus Interface (EBI) controls the external memory or peripheral devices via
an 8- or 16-bit databus and is programmed through the APB. Each chip select line has
its own programming register.
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Bridge. The AMBA Bridge drives the APB,
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