CD1865 Datasheet, PDF (121/150 Pages) Intel Corporation – Intelligent Eight-Channel Communications Controller

Intelligent Eight-Channel Communications Controller — CD1865
9.4.10
These two registers contain the 16-bit pre-load value for the Receive Bit Rate Counter. This count
establishes the basic Receiver Clock Rate, which must be 16 times the required Receiver Bit Rate.
These registers are reset to a ‘0’ by RESET*. The period established for the 16 times Receiver
Clock Rate is equal to the RBPR 16-bit binary value times the System Clock (CLK) Period.
Transmit Bit Rate Period Registers (High/Low)
Register Name: TBPRH
Register Description: Transmit Bit Rate Period Register (High)
Default Value: 0
Access: Read/Write
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Transmit Bit Rate Divisor Byte
Bit 2
8-Bit Hex Address: $39
Intel Hex Address: $72
Motorola Hex Address: $73
Bit 1
Bit 0
Register Name: TBPRL
Register Description: Transmit Bit Rate Period Register (Low)
Default Value: 0
Access: Read/Write
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Transmit Bit Rate Divisor Byte
Bit 2
8-Bit Hex Address: $3A
Intel Hex Address: $74
Motorola Hex Address: $75
Bit 1
Bit 0
9.4.11
These two registers contain the 16-bit pre-load value for the Transmit Bit Rate Counter. This count
establishes the Transmitter Clock Rate, which must be 16 times the required Transmitter Bit Rate.
The precise period established for the 16 times Transmitter Clock is equal to the RBPR 16-bit
binary value times the System Clock (CLK) Period. These registers are reset to a ‘0’ by RESET*.
Special Character Register 1
Register Name: SCHR1
Register Description: Special Character Register 1
Default Value: 0
Access: Read/Write
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Special Character 1
Bit 2
8-Bit Hex Address: $09
Intel Hex Address: $12
Motorola Hex Address: $13
Bit 1
Bit 0
This register stores the right-justified bit pattern for Special Character 1. Unused bits must be a ‘0’.
During receive, this character is one of the four characters compared with the received data for
special-character recognition. If a match occurs with one of these four characters, it is noted in the
Receiver Status FIFO entry accompanying the received character unless a double-character
compare is enabled. In this case, the Receive Status FIFO entry is not made until both characters
are compared and matched.
During transmit, this register contains the characters that are sent as a result of the Send Special
Character 1 command. If two-character sequences are enabled, Characters 1 and 3 are sent.
Datasheet
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