Pin Descriptions - Atmel AT90S8515-8PI Manual

The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly
connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction
executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times
faster than conventional CISC microcontrollers.
The AT90S4414/8515 provides the following features: 4K/8K bytes of In-System Programmable Flash, 256/512 bytes
EEPROM, 256/512 bytes SRAM, 32 general purpose I/O lines, 32 general purpose working registers, flexible
timer/counters with compare modes, internal and external interrupts, a programmable serial UART, programmable Watch-
dog Timer with internal oscillator, an SPI serial port and two software selectable power saving modes. The Idle Mode stops
the CPU while allowing the SRAM, timer/counters, SPI port and interrupt system to continue functioning. The power down
mode saves the register contents but freezes the oscillator, disabling all other chip functions until the next external interrupt
or hardware reset.
The device is manufactured using Atmel's high density nonvolatile memory technology. The on-chip in-system programma-
ble Flash allows the program memory to be reprogrammed in-system through an SPI serial interface or by a conventional
nonvolatile memory programmer. By combining an enhanced RISC 8-bit CPU with In-System Programmable Flash on a
monolithic chip, the Atmel AT90S4414/8515 is a powerful microcontroller that provides a highly flexible and cost effective
solution to many embedded control applications.
The AT90S4414/8515 AVR is supported with a full suite of program and system development tools including: C compilers,
macro assemblers, program debugger/simulators, in-circuit emulators, and evaluation kits.
Comparison Between AT90S4414 and AT90S8515
The AT90S4414 has 4K bytes of In-System Programmable Flash, 256 bytes of EEPROM and 256 bytes of internal SRAM.
The AT90S8515 has 8K bytes of In-System Programmable Flash, 512 bytes of EEPROM and 512 bytes of internal SRAM.
Table 1 summarizes the different memory sizes for the two devices.
Table 1. Memory Size Summary
Part
AT90S4414
AT90S8515

Pin Descriptions

VCC
Supply voltage
GND
Ground
Port A (PA7..PA0)
Port A is an 8-bit bidirectional I/O port. Port pins can provide internal pull-up resistors (selected for each bit). The Port A
output buffers can sink 20mA and can drive LED displays directly. When pins PA0 to PA7 are used as inputs and are
externally pulled low, they will source current if the internal pull-up resistors are activated. The Port A pins are tri-stated
when a reset condition becomes active, even if the clock is not active.
Port A serves as Multiplexed Address/Data input/output when using external SRAM.
Flash
4K bytes
8K bytes
AT90S4414/8515
EEPROM
256 bytes
512 bytes
SRAM
256 bytes
512 bytes
3