ATAR862-3_07 Datasheet, PDF (95/112 Pages) ATMEL Corporation – Microcontroller with UHF ASK/FSK Transmitter

ATAR862-3
Figure 24-18. FSK Modulation
T3R
0123401234012340120120120120120120120123401
Counter 3
CM31
CM32
SO
0
1
0
T3O
24.5
Microcontroller Block
The microcontroller block is a multichip device which offers a combination of a MARC4-based
microcontroller and a serial E2PROM data memory in a single package. A microcontroller is
used and as serial E2PROM the U505M. Two internal lines can be used as chip-to-chip link in a
single package. The maximum internal data communication frequency between the microcon-
troller block and the U505M over the chip link (MCL_SC and MCL_SD) is f_{SC_MCL} = 500 kHz.
The microcontroller and the EEPROM portions of this multi-chip device are equivalent to their
respective individual component chips, except for the electrical specification.
24.5.1
Internal 2-wire Multi-chip Link
Two additional on-chip pads (MCL_SC and MCL_SD) for the SC and the SD line can be used as
chip-to-chip link for multi-chip applications. These pads can be activated by setting the MCL bit
in the SISC register.
Figure 24-19. Link between the Microcontroller Block and U505M
U505M
SCL
SDA
Multi chip link
V _DD
BP40/SC
BP10
MCL_SC
MCL_SD
Microcontroller
V _SS
BP43/SD
BP13
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4556H–4BMCU–07/07