Preliminary Preliminary User's Manual l TQMaX4XxL UM 0001 l © 2022, TQ-Systems GmbH
Page 9
Attention: Malfunction
Please take note of the latest AM64x/AM243x errata (4).
3.2.2
Booting
3.2.2.1
Boot source
The boot source is selected via the boot strapping pins of the AM64x / AM243x. The signals are directly routed to the LGA balls
and will be available again as GPIO after reading the boot configuration.
After the release of MCU_PORz the boot configuration is read in at the BOOTMODE[15:0] pins. Independent of the boot device,
the ROM bootloader is executed first, which assists in reading and executing the application code. The data can be read and
loaded either directly from the memory device or by a peripheral.
The following figure shows the implementation of boot strapping on the module:
Figure 4: Block diagram Boot-Strapping
According to the Reference Manual (3) the general boot configuration at the TQMaX4XxL can be set as follows:
Table 4: Selecting the General Boot Configuration
Boot configuration pin
Setting
TQMaX4XxL
BOOTMODE[15:14]
Reserved, fixed to 0
00
BOOTMODE[13:10]
Select the backup boot mode, if primary boot device failed
Don't care
BOOTMODE[9:3]
See following chapters for boot devices
-
BOOTMODE[2:0]
Ref Clock Select:
000 = 19.2 MHz
001 = 20 MHz
010 = 24 MHz
011 = 25 MHz
100 = 26 MHz
101 = 27 MHz
110 = Reserved
111 = Reserved
011
Attention: Malfunction
All BOOTMODE[15:00] signals must have either a pullup (to V_1V8) or pulldown (to Ground). Undefined
levels can lead to a malfunction during booting.
