XA-G39 NXP Semiconductors, XA-G39 Datasheet - Page 12

• Manufacturer Part Number: XA-G39
• Description: Xa 16-bit Microcontroller Family Xa 16-bit Microcontroller 32k Flash/1k Ram, Watchdog, 2 Uarts
• Manufacturer: NXP Semiconductors

Philips Semiconductors
In-System Programming (ISP)
In-System Programming (ISP) is performed without removing the
microcontroller from the system. The In-System Programming (ISP)
facility consists of a series of internal hardware resources coupled
with internal firmware to facilitate remote programming of the
XA-G39 through the serial port. This firmware is provided by Philips
and embedded within each XA-G39 device.
The Philips In-System Programming (ISP) facility has made in-circuit
programming in an embedded application possible with a minimum
of additional expense in components and circuit board area.
The ISP function uses five pins: TxD, RxD, V
Figure 4). Only a small connector needs to be available to interface
your application to an external circuit in order to use this feature.
The V
allowed to exceed datasheet limits.
ISP increases I
Free ISP software is available on the Philips web site: “WinISP”
1. Direct your browser to the following page:
2. Download “WinISP.exe”
3. Execute WinISP.exe to install the software
Free ISP software is also available from the Embedded Systems
Academy: “FlashMagic”
1. Direct your browser to the following page:
2. Download Flashmagic
3. Execute “flashmagic.exe” to install the software
2002 Mar 13
V
5.0 V
5.0 V
CC
XA 16-bit microcontroller family
32K Flash/1K RAM, watchdog, 2 UARTs
http://www.semiconductors.com/mcu/download/80C51/flash/
http://www.esacademy.com/software/flashmagic/
PP
supply should be adequately decoupled and V
DD
V
V
5.0 V
5.0 V
by less than 1mA.
CC
PP
RST
XTAL2
XTAL1
V
OSC FREQ
22 MHz
30 MHz
SS
Figure 4. In-System Programming with a Minimum of Pins
SS
, V
DD
I
75 mA typical
90 mA typical
, and V
DD
V
TxD
RxD
V
DD
PP
PP
not
PP
(see
12
There is also an application note available that deals with In-System
Programming (AN716). At www.philipsmcu.com, search for “ISP”,
then select AN716 from the search results.
Using In-System Programming (ISP)
ISP mode is entered by holding PSEN low, asserting, un-asserting
RESET, then releasing PSEN. When ISP mode is entered, the
default loader first disables the watchdog timer to prevent a
watchdog reset from occurring during programming.
The ISP feature allows for a wide range of baud rates to be used in
the application, independent of the oscillator frequency. It is also
adaptable to a wide range of oscillator frequencies. This is
accomplished by measuring the bit-time of a single bit in a received
character. This information is then used to program the baud rate in
terms of timer counts based on the oscillator frequency. The ISP
feature requires that an initial character (a lowercase f) be sent to
the XA-G39 to establish the baud rate. The ISP firmware provides
auto-echo of received characters.
Once baud rate initialization has been performed, the ISP firmware
will only accept specific Intel Hex-type records. Intel Hex records
consist of ASCII characters used to represent hexadecimal values
and are summarized below:
In the Intel Hex record, the “NN” represents the number of data
bytes in the record. The XA-G39 will accept up to 16 (10H) data
bytes. The “AAAA” string represents the address of the first byte in
the record. If there are zero bytes in the record, this field is often set
to 0000. The “RR” string indicates the record type. A record type of
“00” is a data record. A record type of “01” indicates the end-of-file
mark. In this application, additional record types will be added to
indicate either commands or data for the ISP facility. The maximum
number of data bytes in a record is limited to 16 (decimal). ISP
commands are summarized in Table 1.
As a record is received by the XA-G39, the information in the record
is stored internally and a checksum calculation is performed. The
:NNAAAARRDD..DDCC<crlf>
V
5V 5%
TxD
RxD
V
DD
SS
SUPPLY OR +12V 5%
MC145406, MAX232,
OR EQUIVALENT
TRANSCEIVER
FOR USE WITH WINISP OR FLASHMAGIC
RS-232
FEMALE
DB-9
SU01593
XA-G39
Preliminary data
2
3
5