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Boot Assist Module (BAM)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
9-9
Figure 9-5. FlexCAN Bit Timing
The eSCI is configured for one start bit, eight data bits, no parity, and one stop bit. It operates at a
baud rate = system clock / 832. (See
NOTE
The BAM program during the serial download routine reconfigures the
software watchdog timer timeout (SWT_TO) from a default of 0x2_7100 to
0x800_0000. The SWT is always clocked from the 16 MHz IRC.
The BAM program ignores eSCI errors. All received data is assumed to be good and is echoed out on the
TXD_A signal.
Upon reception of a valid CAN message with ID = 0x011 that contains 8 bytes of data, or an eSCI byte,
the BAM program transitions to one of two serial boot sub-modes: CAN serial-boot mode or eSCI
serial-boot mode.
Table 9-6. Serial-Boot Mode—Baud Rates
Crystal
Frequency
(MHz)
SCI Baud Rate
(baud)
CAN Baud Rate
(baud)
f
extal
f
extal
/ 832
f
extal
/ 40
8
9600 200K
12
14400 300K
16
19200 400K
20
24000 500K
40
48000
1M
SYNC_SEG
Time segment 1
Time segment 2
Sample point
NRZ signal
Transmit point
1
Time quanta
Time quanta
Time quanta
7 2
1 bit time
1 time quanta = 4 system clock periods
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...