PSB2186N-V11TR Infineon Technologies, PSB2186N-V11TR Datasheet - Page 77

• Manufacturer Part Number: PSB2186N-V11TR
• Description: IC ISDN SUBSCRIB ACCESS 44-PLCC
• Manufacturer: Infineon Technologies

Specifications of PSB2186N-V11TR

• Controller Type: Subscriber Access Controller (ISDN)
• Interface: 4-Wire SPI Serial
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 17mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-PLCC
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Other names: PSB2186N-V11INTR; PSB2186N-V11TR

Functional Description
2.7.5.2
Additional General Considerations when Using the Auto Mode
a)Switching from auto-mode to non-auto mode.
As mentioned in the introduction the auto mode is only applicable in the states 7 and 8 of the
LAPD. Therefore whenever these states have to be left (which is indicated by a "Mode:NAM"
text) there are several actions to be taken that could not all be detailed in the SDL diagrams:
a.1)write non-auto mode and TMD = 0 into the mode register.
a.2)write the timer register with an arbitrary value to stop it. The timer T200 as specified in the
LAPD protocol is implemented in the hardware only in the states 7 and 8; in all other states this
or any other timer-procedure has to be done by the software with the possible use of the timer
in external timer mode.
a.3)read the WFA bit of the STAR2 register and store it in a software variable. The information
in this bit may be necessary for later decisions. When switching from auto mode to non-auto
mode XPR interrupts may be lost.
a.4)In the non-auto mode the software has to decode I-, U- and S frames because I and S
frames are only handled autonomously in the auto-mode.
a.5)The RSC and PCE interrupts, the contents of the STAR2 register and the RRNR bit in the
STAR register are only meaningful within the auto-mode.
a.6)leave some time before RHR or XRES is written to reset the counters, as a currently sent
frame may not be finished yet.
b)What has to be written to the XFIFO?
In the legend description when the software has to write contents of a frame to the XFIFO only
"XFIFO" is shown in the corresponding box. We shall give here a general rule of what has to
be written to the XFIFO:
a) For sending an I frame with CMDR:XIF, only the information field content, i.e. no SAPI, TEI,
Control field should be written to the XFIFO.
b) For sending a U frame or any other frame with CMDR:XTF, the SAPI, TEI and the control
field has to be written to the XFIFO.
c)The interrupts XPR and XMR.
The occurence of an XPR interrupt in auto-mode after an XIF command indicates that the
I frame sent was acknowledged and the next I frame can be sent, if STAR2:TREC indicates
state 7 and STAR:RRNR indicates Peer Rec not busy. If Peer Rec is busy after an XPR, the
software should wait for the next RSC interrupt before sending the next I frame. If the XPR
happens to be in the timer recovery state, the software has to poll the STAR2 register until the
state multiple frame established is reached or a TIN interrupt is issued which requires auto
mode to be left (One of these two conditions will occur before the time T200 N200). In non-
auto mode or after an XTF command the XPR just indicates, that the frame was sent
successfully.
Semiconductor Group
77