OM13005,598 NXP Semiconductors, OM13005,598 Datasheet - Page 202

• Manufacturer Part Number: OM13005,598
• Description: BOARD EVAL EM773 METER US PLUG
• Manufacturer: NXP Semiconductors
• Type: Other Power Managementr

Specifications of OM13005,598

• Design Resources: Plug Meter Schematics, Gerber Files USB Dongle Schematics, Gerber Files
• Main Purpose: Power Management, Energy/Power Meter
• Embedded: Yes, MCU, 32-Bit
• Utilized Ic / Part: EM773FHN33,551
• Interface Type: USB
• Maximum Operating Temperature: + 150 C
• Operating Supply Voltage: 1.8 V to 3.6 V
• Product: Power Management Development Tools
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Primary Attributes: -
• Secondary Attributes: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: EM773, OL2381
• Other names: 568-6680

NXP Semiconductors
UM10415
User manual
18.2.3 Criterion for Valid User Code
Criterion for valid user code: The reserved Cortex-M0 exception vector location 7 (offset
0x 0000 001C in the vector table) should contain the 2’s complement of the check-sum of
table entries 0 through 6. This causes the checksum of the first 8 table entries to be 0. The
boot loader code checksums the first 8 locations in sector 0 of the flash. If the result is 0,
then execution control is transferred to the user code.
If the signature is not valid, the auto-baud routine synchronizes with the host via serial port
0. The host should send a ‘?’ (0x3F) as a synchronization character and wait for a
response. The host side serial port settings should be 8 data bits, 1 stop bit and no parity.
The auto-baud routine measures the bit time of the received synchronization character in
terms of its own frequency and programs the baud rate generator of the serial port. It also
sends an ASCII string ("Synchronized<CR><LF>") to the Host. In response to this host
should send the same string ("Synchronized<CR><LF>"). The auto-baud routine looks at
the received characters to verify synchronization. If synchronization is verified then
"OK<CR><LF>" string is sent to the host. Host should respond by sending the crystal
frequency (in kHz) at which the part is running. For example, if the part is running at
10 MHz, the response from the host should be "10000<CR><LF>". "OK<CR><LF>" string
is sent to the host after receiving the crystal frequency. If synchronization is not verified
then the auto-baud routine waits again for a synchronization character. For auto-baud to
work correctly in case of user invoked ISP, the CCLK frequency should be greater than or
equal to 10 MHz.
Once the crystal frequency is received the part is initialized and the ISP command handler
is invoked. For safety reasons an "Unlock" command is required before executing the
commands resulting in flash erase/write operations and the "Go" command. The rest of
the commands can be executed without the unlock command. The Unlock command is
required to be executed once per ISP session. The Unlock command is explained in
Section 18.4 “UART ISP commands” on page
All information provided in this document is subject to legal disclaimers.
Rev. 1 — 10 September 2010
Chapter 18: EM773 Flash memory programming firmware
208.
UM10415
© NXP B.V. 2010. All rights reserved.
202 of 310