
MT9072
Advance Information
112
16.1.2 Master Control Registers (Y00 to Y0F ) Bit Functions
Tables 64 to 78 describe the bit functions of each of the Master Control Registers in the MT9072. Each register
is repeated for each of the 8 framers. Framer 0 is addressed with Y=0, Framer 1 with Y=1, Framer 2 with Y=2,...
Framer 7 with Y=7 (where Y represents the 4 most significant address bits (MSB) A
11
A
10
A
9
A
8
). In addition, a
simultaneous write to all 8 Framers is possible by setting the address A11 to 1 and A10 to A8 to 0. A (0), (1) or
(#) in the “Name” column of these tables indicates the state of the data bits after a hard reset (the RESET pin is
toggled from zero to one), or a software reset (the RST bit in control register address YF1 is toggled from one
to zero or toggling of RSTC in Global Control Register). The (#) indicates that a (0) or (1) is possible.
Bit
Name
Functional Description
15
IMA
(0)
Inverse Mux for ATM Mode.
Setting this bit high allows the IO port to be easily connected to one
of the Mitel IMA devices such as MT90220. DSTi becomes a serial 1.544 Mb/s data stream. C4b
becomes a 1.544 MHz clock that clocks DSTi in on the falling edge. RXFPB becomes a positive
framing pulse that is high for the first bit of the serial T1 stream coming from the DSTo pin. The
data from DSTo is clocked out on the rising edge of RXDLC. Set this pin low for all other
applications. Note that signaling operations CSTi/CSTo do not function in the IMA Mode. The
Global Control Register 900 bit CK1 is ignored for this mode. 8.192 Mbit/s backplane mode is not
supported if IMA mode is selected on any of the framer’s.
14
#
not used.
13
G.802
(0)
G802 Mode.
If set, this bit maps DSTi data channels transparently onto the transmit line data
and maps the receive data onto DSTo channels as per G.802.
12
JYEL
(0)
Japan Yellow Alarm
Set this bit high to select a pattern of 16 ones (111111111111111) as the
ESF yellow alarm. In order to transmit the japan yellow alarm the TESFYEL bit has to be set.
11
TRANSP
(0)
Transparent Mode Select.
In transparent Mode the data present at the DSTi channels are
transparently sent to the T1 interface. The S bit from the DSTi interface (Channel 31 if running at
2.048 Mb/s backplane) is sent to the S bit position of the T1 interface.The rest of the channelized
data is sent unaltered to the T1 interface. Ensure that TCPI of per channel controlis not set.
10
T1DM
(0)
T1DM Mode Select
. Set this bit high to select T1DM Mode. In T1DM the Ft and Fs pattern is the
same as the D4 Mode but a 1011YR0 pattern is sent and detected in Channel 24 of the T1
interface. Bit Y is used to indicate a yellow Alarm and R bit is used by AT&T for a 8 Kb/s
communication channel.
9
ESF
(0)
Extended Super Frame
. Setting this bit enables transmission and reception of the 24 frame
superframe DS1 protocol.
8
(0)
not used.
7
CXC
(0)
Cross Check.
Setting this bit in ESF mode enables a cross check of the CRC-6 remainder
before the frame synchronizer pulls into sync. This process adds at least 6 milliseconds to the
frame synchronization time.
6-5
RS1-0
(00)
Reframe Select 1 - 0
. These bits set the criteria for an automatic reframe in the event of framing
bits errors. The combinations available are:
RS1 - 0, RS0 - 0 = sliding window of 2 errors out of 4 frames.
RS1 - 0, RS0 - 1 = sliding window of 2 errors out of 5 frames.
RS1 - 1, RS0 - 0 = sliding window of 2 errors out of 6 frames.
RS1 - 1, RS0 - 1 = no reframes due to framing bit errors.
Note that for T1DM mode, the definition of frame boundary is starting from the channel 1 data
including the synchronization byte(10111YR0) and the following’ S’ bit. The Y and the R bits are
ignored for synchronization.
Table 64 - Framing Mode Select (R/W Address Y00) (T1)