psf2115 ETC-unknow, psf2115 Datasheet - Page 32

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

Semiconductor Group
2
The ISDN PC Adapter Circuit IPAC replaces solutions which are based on ISAC-S TE
PSB 2186 and HSCX-TE PSB 21525. Most of the functions of both devices are
integrated on the IPAC with further modifications and improvements on certain features.
Therefore the functional and operational description is quite similar to these devices.
2.1
The HDLC controller of each channel can be programmed to operate in various modes,
which are different in the treatment of the HDLC frame in receive direction. Thus, the
receive data flow and the address recognition features can be effected in a very flexible
way, which satisfies most requirements.
There are 4 different operating modes which can be set via the MODEB register.
• Non-Auto Mode
• Transparent Mode 1
• Transparent Mode 0
• Extended Transparent Modes 0; 1
2.1.1
Characteristics: address recognition, arbitrary window size.
All frames with valid addresses are forwarded directly to the system memory.
According to the selected address mode, the IPAC can perform a 2-byte or 1-byte
address recognition. If a 2-byte address field is selected, the high address byte is
compared with the fixed value FE
individually programmable values in RAH1 and RAH2 registers.
Similarly, two compare values can be programmed in special registers (RAL1, RAL2) for
the low address byte. A valid address will be recognized in case the high and low byte
of the address field correspond to one of the compare values. Thus, the IPAC can be
called (addressed) with 6 different address combinations. HDLC frames with address
fields that do not match with any of the address combinations, are ignored by the IPAC.
The HDLC control field, data in the I-field and an additional status byte are temporarily
stored in the RFIFOB. The HDLC control field and additional information can also be
read from special registers (RHCRB, RSTAB), however, the register contents are only
valid for the last received frame and values of previous frames are overwritten. If several
frames are stored in the RFIFOB the information should be read from the FIFO contents.
In non-auto mode, all frames are treated similarly.
Functional Description
B-Channel Operation
Non-Auto Mode (MODEB: MDS1, MDS0 = 01)
H
or FC
(MODEB: MDS1, MDS0 = 01)
(MODEB: MDS1, MDS0, ADM = 101)
(MODEB: MDS1, MDS0, ADM = 100)
(MODEB: MDS1, MDS0 = 11)
32
H
(group address) as well as with two
Functional Description
PSB 2115
PSF 2115
11.97