RCVDL56DPFL/SP, RCV56DPFL/SP, and RCV336DPFL/SP Designer’s Guide
1119
14-3
14.1.3 K56flex Bit Definitions
39Bh:7 - A-law /
µ
-law Selection. When set, A-law is enabled; when reset,
µ
-law is enabled. If the modems are configured
opposite of each other, they will automatically fall back to V.34.
406h:0 - K56flex Enable. If set, K56flex is enabled; if reset, K56flex is disabled.
406h:2 - Robbed Bit Signaling Mode Enable. If robbed bit signaling is known to be used, this bit should have been on the
server modem. This bit may also be set on client modem to inform the server modem that robbed bit signaling is being used
(if known) in the event the server modem does not have this bit set.
406h:6 - Auto Robbed Bit Detection [client modem only). If set, the modem will automatically detect robbed bit signaling
and inform the server modem. The server modem will automatically adjust its transmitter for robbed bit signaling.
401h:0 - K56flex Handshake in Progress. When set, this status bit indicates the modems are proceeding with a K56flex
handshake. (This bit will set at end of V.8 after SECTXB or SECRXB = 22h.)
401h:5 - K56flex Detected. When set, this status bit indicates a remote K56flex modem has been detected. (This bit will set
at end of V.8 after SECTXB or SECRXB = 22h.) Applicable only if 406h:0 = 1.
408h - Remote K56flex Code Version Number. This code version number is an ASCII number received during INFO0
which may be used to identify the remote modem type. The code revision number is always odd for server modem and even
for client modem.
409h - Desired K56flex Receive Speed. See Table 14-1.
604h - Maximum Receive Rate Mask. See Table 14-1.
605h - Maximum Transmit Rate Mask. See Table 14-1.
The NEWC bit should be set after control bits have been setup as desired.
Note: There are no new bits added to the interface memory map except the SPEED bits now span bits 0-4 of register 0Eh
when in K56flex and V.34 modes.
14.1.4 K56flex
Handshake
The K56flex handshake is very similar to that of V.34. The modems go through a slightly modified V.8 sequence after which
they exchange INFO0 parameters. Each modem then independently sends a probe signal followed by an exchange of
INFO1 parameters. A half duplex TRN is then sent by each modem, starting with the server modem, followed by a full
duplex TRN and an exchange of MP parameters. The handshake can be followed through the use of the SECTXB and
SECRXB registers as in V.34 mode. After Phase 1 , the states are the same for both answer and originate mode. The
handshake states are:
Phase 1
Phase 2
Phase 3
Phase 4
Client
Phase 1
Phase 2
Phase 3
Phase 4
Server
1119F14-1
Handshake Sequence
Client and Server States During Phase 1
Answer mode:
SECTXB = 0,1,2
SECRXB = 0
Originate mode:
SECTXB = 0,3,5
SECRXB = 1
Client States During Phase 2 (answer & originate mode)
SECTXB = 20,21,22,28,29,24,25,2C
SECRXB = 20,22,23,27,28,29,2A,2D,2B,24,25,2C,2D,2E,2F
Summary of Contents for RC336DPFL
Page 193: ...INSIDE BACK COVER NOTES ...