MC145574AAC Freescale Semiconductor, MC145574AAC Datasheet - Page 107

• Manufacturer Part Number: MC145574AAC
• Description: IC TRANSCEIVER ISDN 32-LQFP
• Manufacturer: Freescale Semiconductor
• Type: Transceiverr

Specifications of MC145574AAC

• Voltage - Supply: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Drivers/receivers: -
• Protocol: -
• Lead Free Status / Rohs Status: Compliant

MOTOROLA
13.1.1
13.1.2
13.1
The MC145574 can be configured in several different modes for different applications. The following
sections describe the various configurations available for the NT and TE modes.
NT CONFIGURATIONS
To select NT mode, the TE/NT pin must be held low. The NT device can operate in a mixture of different
configurations. How each aspect of the NT’s operation is selected is discussed separately in the follow-
ing sections. However, for a broad view of the NT’s various flavors, the NT family tree is shown in
Figure 13–1.
NT Fixed or Adaptive Timing
The receiver/demodulator of the NT can operate in two different modes depending on the type of
loop that the device is connected to. These modes are called fixed and adaptive timing modes. The
mode of operation is chosen by the state of Pin 6. When this pin is held low the device is in adaptive
mode, and when held high the device is in fixed timing mode. The choice of mode is dependent on
the loop characteristics, and the intention is that fixed timing should be used for short passive bus
configurations and adaptive timing used for all others. However, the performance of the timing recovery
circuit employed in the MC145474/75, and also in the MC145574, allows the use of adaptive timing
in all loop configurations. Thus, it is recommended that adaptive timing be used in all configurations.
It is also possible to select fixed timing mode via the SCP/GCI control bit OR8(2). The FIX pin is inter-
nally OR’d with this SCP/GCI bit, and one should note that in the NT Terminal mode, this is the only
way to select fixed timing. The FIX pin should be held low if register programming is to be used.
NT Master or Slave
In NT mode, the IDL2/GCI interface can be selected either as a master or a slave. This selection
is done via Pin 5. When Pin 5 is held low, slave mode is selected. When it is held high, master mode
is selected.
NT1 STAR
NT (NORMAL MODE)
MASTER
NT TERMINAL
Freescale Semiconductor, Inc.
For More Information On This Product,
FIXED TIMING
NT1 STAR
Go to: www.freescale.com
NT (NORMAL MODE)
Figure 13–1. NT Family Tree
SLAVE
MC145574
NT TERMINAL
DEVICE CONFIGURATIONS
NT
NT1 STAR
NT (NORMAL MODE)
MASTER
NT TERMINAL
ADAPTIVE TIMING
NT1 STAR
NT (NORMAL MODE)
SLAVE
13
NT TERMINAL
13–1