Atmel AT90S8515-4 User Manual
4
AT90S8515
0841GS–09/01
one clock cycle. The resulting architecture is more code efficient while achieving
throughputs up to ten times faster than conventional CISC microcontrollers.
throughputs up to ten times faster than conventional CISC microcontrollers.
The AT90S8515 provides the following features: 8K bytes of In-System Programmable
Flash, 512 bytes EEPROM, 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 Watchdog 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 con-
tents but freezes the oscillator, disabling all other chip functions until the next external
interrupt or hardware reset.
Flash, 512 bytes EEPROM, 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 Watchdog 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 con-
tents 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 Programmable Flash allows the program memory to be repro-
grammed 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 Pro-
grammable Flash on a monolithic chip, the Atmel AT90S8515 is a powerful
microcontroller that provides a highly flexible and cost-effective solution to many embed-
ded control applications.
The On-chip In-System Programmable Flash allows the program memory to be repro-
grammed 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 Pro-
grammable Flash on a monolithic chip, the Atmel AT90S8515 is a powerful
microcontroller that provides a highly flexible and cost-effective solution to many embed-
ded control applications.
The AT90S8515 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.
tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit
emulators and evaluation kits.
Pin Descriptions
VCC
Supply voltage.
GND
Ground.
Port A (PA7..PA0)
Port A is an 8-bit bi-directional I/O port. Port pins can provide internal pull-up resistors
(selected for each bit). The Port A output buffers can sink 20 mA and can drive LED dis-
plays 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.
(selected for each bit). The Port A output buffers can sink 20 mA and can drive LED dis-
plays 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.
Port B (PB7..PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors. The Port B output
buffers can sink 20 mA. As inputs, Port B pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset
condition becomes active, even if the clock is not active.
buffers can sink 20 mA. As inputs, Port B pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset
condition becomes active, even if the clock is not active.
Port B also serves the functions of various special features of the AT90S8515 as listed
on page 66.
on page 66.
Port C (PC7..PC0)
Port C is an 8-bit bi-directional I/O port with internal pull-up resistors. The Port C output
buffers can sink 20 mA. As inputs, Port C pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset
condition becomes active, even if the clock is not active.
buffers can sink 20 mA. As inputs, Port C pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset
condition becomes active, even if the clock is not active.
Port C also serves as address output when using external SRAM.
Port D (PD7..PD0)
Port D is an 8-bit bi-directional I/O port with internal pull-up resistors. The Port D output
buffers can sink 20 mA. As inputs, Port D pins that are externally pulled low will source
buffers can sink 20 mA. As inputs, Port D pins that are externally pulled low will source