XA-G49 Datasheet, PDF (10/42 Pages) NXP Semiconductors – XA 16-bit microcontroller family 64K FLASH/2K RAM, watchdog, 2 UARTs

Philips Semiconductors
XA 16-bit microcontroller family
64K Flash/2K RAM, watchdog, 2 UARTs
Preliminary specification
XA-G49
FLASH EPROM MEMORY
GENERAL DESCRIPTION
The XA-G49 Flash memory augments EPROM functionality with
in-circuit electrical erasure and programming. The Flash can be read
and written as bytes. The Chip Erase operation will erase the entire
program memory. The Block Erase function can erase any single
Flash block. In-circuit programming and standard parallel
programming are both available. On-chip erase and write timing
generation contribute to a user friendly programming interface.
The XA-G49 Flash reliably stores memory contents even after
10,000 erase and program cycles. The cell is designed to optimize
the erase and programming mechanisms. In addition, the
combination of advanced tunnel oxide processing and low internal
electric fields for erase and programming operations produces
reliable cycling. For In-System Programming, the XA-G49 can use a
single +5 V power supply. Faster In-System Programming may be
obtained, if required, through the use of a +12 V V_PP supply.
Parallel programming (using separate programming hardware) uses
a +12 V V_PP supply
FEATURES
• Flash EPROM internal program memory with Single Voltage
Programming and Block Erase capability.
• Internal 2k byte fixed boot ROM, containing low-level
programming routines and a default loader. The Boot ROM can be
turned off to provide access to the full 64k byte Flash memory.
• Boot vector allows user provided Flash loader code to reside
anywhere in the Flash memory space. This configuration provides
flexibility to the user.
• Default loader in Boot ROM allows programming via the serial port
without the need for a user provided loader.
• Up to 1 Mbyte external program memory if the internal program
memory is disabled (EA = 0).
• Programming and erase voltage: V_PP = V_DD (single 5V ±5% chip
power supply), or 12V ±5% for In System Programming. Using
12V V_PP for ISP may improve programming and erase time.
• Read/Programming/Erase:
– Byte-wise read (60 ns access time at 4.5 V).
– Byte Programming (40 ms).
– Typical erase times:
Block Erase (8k bytes or 16k bytes) in t.b.d. seconds.
Full Erase (64k bytes) in t.b.d. seconds.
• In-circuit programming via user selected method, typically RS232
or parallel I/O port interface.
• Programmable security for the code in the Flash
• 1,000 minimum erase/program cycles each byte over operating
temperature range
• 10 year minimum data retention.
CAPABILITIES OF THE PHILIPS 89C51
FLASH-BASED MICROCONTROLLERS
Flash organization
The XA-G49 contains 64k bytes of Flash program memory. This
memory is organized as 5 separate blocks. The first two blocks are
8k bytes in size, filling the program memory space from address 0
through 3FFF hex. The final three blocks are 16k bytes in size and
occupy addresses from 4000 through FFFF hex.
Figure 3 depicts the Flash memory configuration.
Flash Programming and Erasure
The XA-G49 Flash microcontroller supports a number of
programming possibilities for the on-chip Flash memory. The Flash
memory may be programmed in a parallel fashion on standard
programming equipment in a manner similar to an EPROM
microcontroller. The XA-G49 microcontroller is able to program its
own Flash memory while the application code is running. Also, a
default loader built into a Boot ROM allows programming blank
devices serially through the UART.
Using any of these types of programming, any of the individual blocks
may be erased separately, or the entire chip may be erased.
Programming of the Flash memory is accomplished one byte at a time.
Boot ROM
When the microcontroller programs its own Flash memory, all of the
low level details are handled by code that is permanently contained
in a 2k byte “Boot ROM” that is separate from the Flash memory. A
user program simply calls the entry point with the appropriate
parameters to accomplish the desired operation. Boot ROM
operations include things like: erase block, program byte, verify
byte, program security lock bit, etc. The Boot ROM overlays the
program memory space at the top of the address space from F800
to FFFF hex, when it is enabled by setting the ENBOOT bit at
AUXR1.7.. The Boot ROM may be turned off so that the upper 2k
bytes of Flash program memory are accessible for execution.
ENBOOT and PWR_VLD
Setting the ENBOOT bit in the AUXR register enables the Boot
ROM and activates the on-chip V_PP generator if V_PP is connected to
V_DD rather than 12V externally. The PWR_VLD flag indicates that
V_PP is available for programming and erase operations. This flag
should be checked prior to calling the Boot ROM for programming
and erase services. When ENBOOT is set, it typically takes
5 microseconds for the internal programming voltage to be ready.
The ENBOOT bit will automatically be set if the status byte is
non-zero during reset, or when PSEN is low, ALE is high, and EA is
high at the falling edge of reset. Otherwise, ENBOOT will be cleared
during reset.
When programming functions are not needed, ENBOOT may be
cleared. This enables access to the 2k bytes of Flash code memory
that is overlaid by the Boot ROM, allowing a full 64k bytes of Flash
code memory.
2000 Apr 03
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