sx20ac Parallax, Inc., sx20ac Datasheet - Page 3

• Manufacturer Part Number: sx20ac
• Description: Configurable Communications Controllers With Ee/flash Program Memory, In-system Programming Capability And On-chip Debug
• Manufacturer: Parallax, Inc.

Parallax SX20AC/SX28AC
1.2.
75 MIPS Performance
EE/FLASH Program Memory and SRAM Data Memory
CPU Features
Fast and Deterministic Interrupt
Flexible I/O
© Parallax Inc.
• SX20AC/SX28AC: DC - 75 MHz
• SX20AC/SX28AC: as low as 13.3 ns instruction
• 1 instruction per clock for most instructions (skips
• Access time of < 13.3 ns provides single cycle
• EE/Flash rated for > 10,000 rewrite cycles
• 2048 Words EE/Flash program memory
• 136x8 bits SRAM data memory
• Compact, RISC-like instruction set
• All non-branch instructions are single cycle
• Eight-level push/pop hardware stack for subroutine
• Fast table lookup capability through run-time
• Totally predictable program execution rate for
• Jitter-free 3-cycle internal interrupt response
• Hardware context save/restore of key resources such
• External wakeup/interrupt capability on Port B
• All port pins individually programmable as I/O
• Inputs are TTL or CMOS level selectable
• All pins have selectable internal pull-ups
• Selectable Schmitt Trigger inputs on Ports B and C
• All output pins capable of sourcing/sinking 30 mA
• Port A outputs have symmetrical drive
• Analog comparator support on Port B (RB0 OUT,
• Selectable I/O operation synchronous to the
cycle, 39.9 ns internal interrupt response
require 2 clocks, branches require 3 clocks, IREAD
requires 4)
access
operation
readable code (IREAD instruction)
precise real-time applications
as PC, W, STATUS, and FSR within the 3-cycle
interrupt response time
(8 pins)
RB1 IN-, RB2 IN+)
oscillator clock
Key Features
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Hardware Peripheral Features
Packages
Programming and Debugging Support
Software Support
• One 8-bit Real Time Clock/Counter (RTCC) with
• Watchdog Timer (shares the RTCC prescaler)
• Analog comparator
• Brown-out detector
• Multi-Input Wakeup logic on 8 pins
• Internal RC oscillator with configurable rate from
• Power-On-Reset
• 20-pin SSOP, 28-pin DIP/SSOP
• On-chip in-system serial programming support via
• On-chip in-system debugging support logic
• Real-time emulation, full program debug, and
• The language options available: Parallax Assembly;
• Native assembly instruction set
• Expanded assembly instruction set available in the
• Parallax SX/B compiler (BASIC)
• Several “C” compliers available from third-party
programmable 8-bit prescaler
31.25 kHz to 4 MHz
the oscillator pins
integrated development environment offered by the
Parallax SX-Key
Parallax SX/B (BASIC); and CCS SX/C (C)
SASM assembler of the Parallax SX-Key IDE
vendors
®
programming device
Rev 1.6 11/20/2006
www.parallax.com