80C51 8-bit microcontroller family with extended memory;
96 kB Flash with 2 kB RAM
Rev. 02 — 13 November 2003
1. General description
The P89C669 represents the ﬁrst Flash microcontroller based on Philips
Semiconductors’ new 51MX core. The P89C669 features 96 kbytes of Flash program
memory and 2 kbytes of data SRAM. In addition, this device is equipped with a
Programmable Counter Array (PCA), a watchdog timer that can be conﬁgured to
different time ranges through SFR bits, as well as two enhanced UARTs and byte
based I2C-bus serial interface.
Philips Semiconductors’ 51MX (Memory eXtension) core is an accelerated 80C51
architecture that executes instructions at twice the rate of standard 80C51 devices.
The linear address range of the 51MX has been expanded to support up to 8 Mbytes
of program memory and 8 Mbytes of data memory. It retains full program code
compatibility to enable design engineers to re-use 80C51 development tools,
eliminating the need to move to a new, unfamiliar architecture. The 51MX core also
retains 80C51 bus compatibility to allow for the continued use of 80C51-interfaced
peripherals and Application Speciﬁc Integrated Circuits (ASICs).
The P89C669 provides greater functionality, increased performance and overall lower
system cost. By offering an embedded memory solution combined with the
enhancements to manage the memory extension, the P89C669 eliminates the need
for software work-arounds. The increased program memory enables design
engineers to develop more complex programs in a high-level language like C, for
example, without struggling to contain the program within the traditional 64 kbytes of
program memory. These enhancements also greatly improve C Language efﬁciency
for code size below 64 kbytes.
The P89C669 device contains a non-volatile Flash program memory that is both
parallel programmable and serial In-System and In-Application Programmable.
In-System Programming (ISP) allows the user to download new code while the
microcontroller sits in the application. In-Application Programming (IAP) means that
the microcontroller fetches new program code and reprograms itself while in the
system. This allows for remote programming over a modem link. A default serial
loader (boot loader) program in ROM allows serial In-System programming of the
Flash memory via the UART without the need for a loader in the Flash code. For
In-Application Programming, the user program erases and reprograms the Flash
memory by use of standard routines contained in ROM.
The 51MX core is described in more detail in the 51MX Architecture Reference.