PSF21150 INFINEON [Infineon Technologies AG], PSF21150 Datasheet - Page 154

• Manufacturer Part Number: PSF21150
• Description: IPAC-X ISDN PC ADAPTER CIRCUIT
• Manufacturer: INFINEON [Infineon Technologies AG]

– XRES (Transmitter Reset) command, resetting the HDLC transmitter and clearing the
Optionally two additional status conditions can be read by the host:
– XDOV (Transmit Data Overflow), indicating that the data block size has been
– XFW (Transmit FIFO Write Enable), indicating that data can be written to the XFIFOx.
Note: The significant interrupts and commands are underlined as only these are usually
The XFIFO requests service from the microcontroller by setting a bit in the ISTAx
register, which causes an interrupt (XPR, XDU, XMR). The microcontroller can then read
the status register STARx (XFW, XDOV), write data in the FIFO and it can change the
transmit FIFO block size (EXMx.XFBS) if required.
The instant of the initiation of a transmit pool ready (XPR) interrupt after different transmit
control commands is listed in
Table 19
When setting XME the transmitter appends the CRC and the endflag at the end of the
frame. When XTF & XME has been set, the XFIFOx is locked until successful
transmission of the current frame, so a consecutive XPR interrupt also indicates
successful transmission of the frame whereas after XME or XTF the XPR interrupt is
asserted as soon as there is space for one data block in the XFIFOx.
Data Sheet
CMDRx
Register
XTF
XTF & XME
XME
transmit FIFO of any data. After an XRES command the transmitter always sends an
abort sequence, i.e. this command can be used to abort a transmission. Pending
interrupt indications of the transmitter are not cleared by XRES, but have to be cleared
by reading these interutps.
exceeded, i.e. more than 16 or 32 byte (D-channel) or 32 or 64 byte (B-channel) were
entered and data was overwritten.
This status flag may be polled instead of or in addition to XPR.
used during a normal transmission sequence.
XPR Interrupt (Availability of XFIFOx) After XTF, XME Commands
Transmit pool ready (XPR) interrupt initiated ...
as soon as the selected buffer size in the FIFOx is available.
after the successful transmission of the closing flag.
The transmitter always sends an abort sequence.
as soon as the selected buffer size in the FIFO is available,
two consecutive frames share flags.
Table
19.
154
Description of Functional Blocks
PSB 21150
PSF 21150
2000-07-21