Nxp Semiconductors UM10237 ユーザーズマニュアル
UM10237_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 19 December 2008
702 of 792
NXP Semiconductors
UM10237
Chapter 31: LPC24XX On-chip bootloader for flashless parts
[1]
ISP entry after reset uses the on chip IRC and PLL to run the device at CCLK = 14.748 MHz
6.3 Echo <setting>
6.4 Write to RAM <start address> <number of bytes>
The host should send the data only after receiving the CMD_SUCCESS return code. The
host should send the check-sum after transmitting 20 UU-encoded lines. The checksum is
generated by adding raw data (before UU-encoding) bytes and is reset after transmitting
20 UU-encoded lines. The length of any UU-encoded line should not exceed
61 characters(bytes) i.e. it can hold 45 data bytes. When the data fits in less then
20 UU-encoded lines then the check-sum should be of the actual number of bytes sent.
The ISP command handler compares it with the check-sum of the received bytes. If the
check-sum matches, the ISP command handler responds with "OK<CR><LF>" to
host should send the check-sum after transmitting 20 UU-encoded lines. The checksum is
generated by adding raw data (before UU-encoding) bytes and is reset after transmitting
20 UU-encoded lines. The length of any UU-encoded line should not exceed
61 characters(bytes) i.e. it can hold 45 data bytes. When the data fits in less then
20 UU-encoded lines then the check-sum should be of the actual number of bytes sent.
The ISP command handler compares it with the check-sum of the received bytes. If the
check-sum matches, the ISP command handler responds with "OK<CR><LF>" to
Return Code
CMD_SUCCESS |
INVALID_BAUD_RATE |
INVALID_STOP_BIT |
PARAM_ERROR
Description
This command is used to change the baud rate. The new baud rate is effective
after the command handler sends the CMD_SUCCESS return code.
after the command handler sends the CMD_SUCCESS return code.
Example
"B 57600 1<CR><LF>" sets the serial port to baud rate 57600 bps and 1 stop bit.
Table 634. Correlation between possible ISP baudrates and CCLK frequency (in MHz)
ISP Baudrate .vs.
CCLK Frequency
CCLK Frequency
9600
19200
38400
57600
115200
230400
10.0000
+
+
+
11.0592
+
+
+
12.2880
+
+
+
14.7456
+
+
+
+
+
+
15.3600
+
18.4320
+
+
+
19.6608
+
+
+
24.5760
+
+
+
25.0000
+
+
+
Table 633. ISP Set Baud Rate command
Command
B
Table 635. ISP Echo command
Command
A
Input
Setting: ON = 1 | OFF = 0
Return Code
CMD_SUCCESS |
PARAM_ERROR
Description
The default setting for echo command is ON. When ON the ISP command handler
sends the received serial data back to the host.
sends the received serial data back to the host.
Example
"A 0<CR><LF>" turns echo off.