User's Manual

System Overview and Functional Block Descriptions
1322x-LPB Reference Manual, Rev. 1.1
3-8 Freescale Semiconductor
3.5.2 32.768 kHz Crystal Oscillator
Provision is also made for the secondary 32.768 kHz oscillator crystal X2. This oscillator can be used on
the MC1322x for a low power accurate RTC timebase and wake-up state machine. The module comes with
this crystal and its load capacitors C7 and C12 mounted. Although use of the oscillator is optional, the
module is provided ready for use. See Figure 3-9.
Figure 3-9. 32.768 KHz Oscillator Related Circuitry
3.6 FLASH Memory Recovery Jumpers and Erase
The MC1322x has an onboard serial FLASH that stores the memory image that gets loaded into RAM at
boot. If it becomes necessary to change or update the image in FLASH, there are two possible means of
doing so:
• JTAG Debug Port - Using the JTAG debug port and the ARM debug tools, the FLASH image can
be changed.
• Load new FLASH image via UART1 port -
NOTE
The 1322x-LPB provides a header for UART1 that is NOT buffered for
RS232 operation. If users must employ UART1 with the Freescale Test Tool
running on a PC, they must provide an appropriate RS232 interface board to
connect to a PC serial COM port.
— The Freescale BeeKit IDE suite download provides a software tool called “Test Tool”. This
application runs on a PC and can be used with a client running on the MC1322x to test the
platform.
— Test Tool also has the capability to load a new image into the FLASH.
NOTE
The FLASH must be cleared before loading a new image.
The 1322x-LPB has two jumper sites designated as J19 and J20 (see Figure 3-4) that must be used to erase
the FLASH:
1. Short Jumper J19 Pin 1 to Pin 2 with a shorting bar, as well as, short Jumper J20 Pin 1 to Pin 2 with
a second shorting bar
2. Turn on power, push the reset button, and wait a few seconds.
C7
22pF
C12
22pF
X2
32.768kHz
TP10
XTA L_ 32_ OU T
XTA L_ 32_ I N