CD2481 Datasheet, PDF (147/222 Pages) Intel Corporation – Programmable Four-Channel Communications Controller

Programmable Four-Channel Communications Controller — CD2481
9.3.2.2
Transmit Clock Option Register (TCOR)
Register Name: TCOR
Register Description: Transmit Clock Option Register
Default Value: x’00
Access: Byte Read/Write
Bit 7
Bit 6
Bit 5
Bit 4
ClkSel2
ClkSel1
ClkSel0
0
Bit 3
Ext-1X
Intel Hex Address: x’C2
Motorola Hex Address: x’C0
Bit 2
0
Bit 1
LLM
Bit 0
0
This register controls the transmit baud rate generator and Local Loopback mode.
Bits 7:5
These bits select the clock source for the transmit baud rate generator.
ClkSel2
0
0
0
0
1
1
1
1
ClkSel1
0
0
1
1
0
0
1
1
ClkSel0
0
1
0
1
0
1
0
1
Select
Clk 0
Clk 1
Clk 2
Clk 3
Clk 4
Reserved
External clock
Receive clock
Note: See the description of clock options in Section 5.5.
Bit 4
Reserved – must be zero.
Bit 3
Times 1 external clock. This bit is set to ‘1’ when user supplies the data clock on
TxCIN[i] pin whose frequency is equal to the transmit data rate. When using the
external 1× clock or the clock from the receiver’s DPLL, the TBPR must be pro-
grammed to 01h.
Bit 2
Reserved – must be zero.
Bit 1
Local Loopback mode
1 = enables the Local Loopback mode
0 = disables the Local Loopback mode
Bit 0
Reserved – must be zero.
Datasheet
147