peb20560 Infineon Technologies Corporation, peb20560 Datasheet - Page 52

• Manufacturer Part Number: peb20560
• Description: Dsp Oriented Pbx Controller Doc
• Manufacturer: Infineon Technologies Corporation

Semiconductor Group
2.1.2.4
The SACCO (Special Application Communication Controller) is a high level serial
communication controller consisting of two independent HDLC-channels (A +B). It is a
derivative product of the Siemens SAB 82525 (HSCX).
The SACCO essentially reduces the hardware and software overhead for serial
synchronous communication. SACCO channel A can be multiplexed by the D-channel
arbiter to serve multiple subscribers.
In the following section one SACCO channel is described referring to as “SACCO”.
2.1.2.4.1
The SACCO (one channel) provides two independent 64-byte FIFOs for receive and
transmit direction and a sophisticated protocol support. It is optimized for line card
applications in digital exchange systems and offers special features to support:
– Communication between a line card and a group controller
– Communication between terminal equipment and a line card
2.1.2.4.2
All registers and the FIFOs are accessible via the DOC parallel µP-interface. The FIFOs
allocate an address space of 32 bytes each. The data in the FIFOs can be managed by
the CPU- or a DMA-controller.
To enable the use of block move instructions, the top of FIFO-byte is selected by any
address in the reserved range.
Interrupts
The SACCO indicates special events by issuing an interrupt request. The cause of a
request can be determined by reading the interrupt status register ISTA_A/B or
EXIR_A/B. The related register is flagged in the top level ISTA (refer to Figure 3-1).
Three indications are available in ISTA_A/B, another five in the extended interrupt
register EXIR_A/B. An interrupt which is masked in the MASK_A/B is not indicated in the
top level register and the INT-line is not activated. The interrupt is also not visible in the
local registers ISTA_A/B but remains stored internally and will be indicated again when
the corresponding MASK_A/B-bit is reset.
The SACCO-interrupt sources can be splitted in three logical groups:
• Receive interrupts
• Transmit interrupts
• Special condition interrupts
For further information refer to chapter 3.1.4.1 (Data Transmission in Interrupt Mode)
and chapter 3.1.4.3 (Data Reception in Interrupt Mode).
SACCO
Block Diagram
Parallel Interface
(RFS, RPF, RME, EHC)
(XPR, XMR)
(XDU/EXE, RFO)
2-6
Functional Block Description
PEB 20560
2003-08