psf2115 ETC-unknow, psf2115 Datasheet - Page 47

• Manufacturer Part Number: psf2115
• Description: Isdn Adapter Circuit Ipac
• Manufacturer: ETC-unknow

When 32 bytes of a message longer than that are stored in RFIFOD, the CPU is
prompted to read out the data by an RPF interrupt. The CPU must handle this interrupt
before more than 32 additional bytes are received, which would cause a “data overflow”
(figure 16). This corresponds to a maximum CPU reaction time of 16 ms (data rate 16
kbit/s).
After a remaining block of less than or equal to 16 bytes has been stored, it is possible
to store the first 16 bytes of a new message (see figure 16).
The internal memory is now full. The arrival of additional bytes will result in “data
overflow” and a third new message in “frame overflow”.
The generated interrupts are inserted together with all additional information into a wait
line to be individually passed to the CPU.
After an RPF or RME interrupt has been processed, i.e. the received data has been read
from the RFIFOD, this must be explicitly acknowledged by the CPU issuing a RMC
(Receive Message Complete) command.
The IPAC can then release the associated FIFO pool for new data. If there is an
additional interrupt in the wait line it will be generated after the RMC acknowledgment.
Figure 16
Semiconductor Group
31
31
0
0
Message
RFIFOD
Long
Contents of RFIFOD (long message)
Interrupts in
the Queue
RPF
RPF
47
15
16
31
31
0
0
(
(
Message
Message 2
<
<
_
_
RFIFOD
48
32
Long
bytes)
bytes)
1
Functional Description
Interrupts in
the Queue
PSB 2115
PSF 2115
ITD09624
RPF
RME
RME
11.97