PEB22554 SIEMENS [Siemens Semiconductor Group], PEB22554 Datasheet - Page 153

• Manufacturer Part Number: PEB22554
• Description: ICs for Communications
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Semiconductor Group
Receive FIFO (Read) RFIFO
RFIFO
Reading data from RFIFO can be done in an 8-bit (byte) or 16-bit (word) access
depending on the selected bus interface mode. The LSB is received first from the serial
interface.
The size of the accessible part of RFIFO is determined by programming the bits
CCR1.RFT 1 … 0 (RFIFO threshold level). It can be reduced from 32 bytes (RESET
value) down to 2 bytes (four values: 32, 16, 4, 2 bytes).
Data Transfer
Up to 32 bytes/16 words of received data can be read from the RFIFO following an RPF
or an RME interrupt.
RPF Interrupt: A fixed number of bytes/words to be read (32, 16, 4, 2 bytes). The
message is not yet complete.
RME Interrupt: The message is completely received. The number of valid bytes is
determined by reading the RBCL, RBCH registers.
RFIFO is released by issuing the “Receive Message Complete” command (RMC).
Receive Buffer Delay (Read)
RBD
RBD5…RBD0... Receive Elastic Buffer Delay
7
7
RF7
These bits informs the user about the current delay (in time-slots)
through the receive elastic buffer. The delay is updated every 512 or
256 bits (SIC1.RBS1/0). Before reding this register the user has to set
bit DEC.DRBD in order to halt the current value of this register. After
reading RBD updating of this register is enabled. Not valid if the
receive buffer is bypassed.
000000 = delay < 1 time-slot
:
:
111111 = delay >63 time-slots
RBD5
RBD4
153
RBD3
RBD2
Operational Description E1
RBD1
0
0
RBD0
RF0
PEB 22554
(x00/x01)
(x49)
09.98