
PRELIMINARY
S3C6400X RISC MICROPROCESSOR
MODEM INTERFACE
23-1
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
23
MODEM INTERFACE
Overview
This specification defines the interface between the Base-band Modem (MSM) and the Application Processor for
the data-exchange of these two devices (refer Figure 23-1). For the data-exchange, the AP (Application
Processor, S3C6400X) has a dual-ported SRAM buffer (on-chip) and the Modem chip can access that SRAM
buffer using a typical asynchronous-SRAM interface.
The size of the SRAM buffer is 8KByte. For the buffer status and Interrupt Requests, this specification also
specifies a few of pre-defined special addresses.
The Modem chip can write data in the data buffer and write interrupt control-data to the interrupt-port address for
the interrupt request to the AP. The AP reads that data when an interrupt request is accepted and the interrupt is
cleared when the AP accesses the interrupt-port address. In the same manner, the AP can write data in the data
buffer and write interrupt control-data to the interrupt-port address for the interrupt request to the Modem chip.
AHB
bus
Figure 23-1 The interface with the Modem chip and the MSM I/F block diagram