Datasheet

DS21Q50
53 of 87
15. USER-CONFIGURABLE OUTPUTS
There are two user-configurable output pins for each transceiver, OUTA and OUTB. These pins can be
programmed to output various clocks, alarms for line monitoring, logic 0 and 1 levels to control external
circuitry, or access transmit data between the framer and transmit line interface unit. OUTA and OUTB
can be active low or active high when operating as clock and alarm outputs. OUTA is active high if
OUTAC.4 =1 and active low if OUTAC.3 = 0. OUTB is active high if OUTBC.4 = 1 and active low if
OUTBC.4 = 0 (Table 15-1). Mode 0000 is selected for controlling external circuitry. In this
configuration, the OUTA pin follows OUTAC.4 and the OUTB pin follows OUTBC.4.
The OUTAC register also contains a control bit for CMI operation. See Section 16 for details about CMI
operation.
Register Name:
OUTAC
Register Description:
OUTA Control Register
Register Address:
1A Hex
Bit 7 6 5 4 3 2 1 0
Name TTLIE CMII CMIE OA4 OA3 OA2 OA1 OA0
NAME BIT FUNCTION
TTLIE 7
TTL Input Enable. When this bit is set, the receiver can accept TTL positive and negative
data at the RTIP and RRING inputs. The data is clocked in on the falling edge of MCLK.
CMII 6
CMI Invert. See Section 17
for details.
0 = CMI input data not inverted
1 = CMI input data inverted
CMIE 5
CMI Enable. See Section 17
for details.
0 = CMI disabled
1 = CMI enabled
OA4 4 OUTA Control Bit 4. Inverts OUTA output.
OA3 3 OUTA Control Bit 3 (Table 15-1)
OA2 2 OUTA Control Bit 2 (Table 15-1)
OA1 1 OUTA Control Bit 1 (Table 15-1)
OA0 0 OUTA Control Bit 0 (Table 15-1)