AIROC™ Bluetooth® system on chip for automotive applications
Microprocessor unit
2
Microprocessor unit
The CYW89820 includes a Cortex® M4 processor with 1 MB of program ROM, 160 KB of data RAM, 16 KB of patch
RAM, and 256 KB of flash. The CM4 has a maximum speed of 96 MHz. The 256 KB of flash is supported by an 8 KB
cache allowing direct code execution from flash at near maximum speed and low power consumption.
The CM4 runs all the BT layers as well as application code. The ROM includes LMAC, HCI, L2CAP, GATT, as well as
other stack layers freeing up most of the flash for application usage.
A standard serial wire debug (SWD) interface provides debugging support. Refer to the “Firmware” on page 21
section for details on the architecture and layers that are included in the ROM.
2.1
Main crystal oscillator
The CYW89820 uses a 24 MHz crystal oscillator (XTAL).
The XTAL must have an accuracy of ±20 ppm as defined by the Bluetooth® specification. Two external load capac-
itors are required to work with the crystal oscillator. The selection of the load capacitors is XTAL-dependent (see
Figure 1).
CL1
XIN
Crystal
XOUT
CL2
Figure 1
Recommended oscillator configuration
Table 2
Reference crystal electrical specifications
Conditions
Parameter
Min
–
Fundamental
Typ
24.000
Max
–
Unit
MHz
–
Nominal frequency
Oscillation mode
–
–
Includes operating temperature
range and aging
Frequency accuracy
–
–
±20
ppm
Equivalent series resistance
Load capacitance
Drive level
–
–
–
–
–
–
–
–
–
8
–
–
60
–
200
2
W
pF
μW
pF
Shunt capacitance
Datasheet
8
002-25826 Rev. *G
2022-09-24
INFINEON [ Infineon ]
