AM79C32A Advanced Micro Devices, AM79C32A Datasheet - Page 42

• Manufacturer Part Number: AM79C32A
• Description: Digital Subscriber Controller (DSC) Circuit
• Manufacturer: Advanced Micro Devices

Transmit Address Register — (TAR) — Read/Write
Address = Indirect 83H
This register contains the address of the packet to be transmitted if the TAR bit is enabled (DMR1 bit 2).
First Received Byte Address Register — (FRAR1–FRAR4) — Read/Write
Address = Indirect FRAR1–FRAR3 = 81H, FRAR4 = 8CH
These registers contain the value to match against the first byte of the incoming address. If DMR1 bits 4–7 are dis-
abled, these registers are ignored.
Second Received Byte Address Register — (SRAR1–SRAR4) — Read/Write
Address = Indirect SRAR1–SRAR3 = 82H, SRAR4 = 8DH
These registers contain the value to match against the first byte of the incoming address. If DMR1 bits 4–7 are dis-
abled, these registers are ignored.
D-Channel Receive Byte Count Register — (DRCR) — Read
Address = Indirect 89H
This register determines the maximum number of bytes in a received packet.
D-Channel Receive Byte Limit Register — (DRLR) — Read/Write
Address = Indirect 84H
This register contains the total number of received bytes.
D-Channel Transmit Byte Count Register — (DTCR) — Read/Write
Address = Indirect 85H
This register contains the total number of transferred bytes.
Random Number Generator Register — (RNGR1, RNGR2) — Read/Write
Address = Indirect RNGR1 = 8AH, RNGR2 = 8BH
These registers control the operation of the Random Number Generator. When read, they display the random num-
ber generated by the chip.
D-Channel Transmit Buffer Register — (DCTB) —Write
D-channel transmit FIFO.
D-Channel Receive Buffer Register — (DCRB) — Read
D-channel receive FIFO.
D-Channel Mode Register 1 — (DMR1) — Read/Write
Address = Indirect 86H
DMR1 controls the enable/disable options for the DLC. It is under sole control of the microprocessor and does not
generate any interrupts. DMR1 is defined in Table 39.
42
Bit
0
1
2
3
4
5
6
7
Logical 1
Enable D-channel Transmit Threshold interrupt (see IR bit 0) Disable interrupt (default value)
Enable D-channel Receive Threshold interrupt (see IR bit 1)
Enable Transmit Address Register
Enable End of Receive Packet interrupt (see DSR1 bit 1)
Enable FRAR1/SRAR1
Enable FRAR2/SRAR2
Enable FRAR3/SRAR3
Enable FRAR4/SRAR4
Table 39. D-Channel Mode Register 1
Am79C30A/32A Data Sheet
Disable interrupt (default value)
Logical 0
Disable Transmit Address Register (default value)
Disable interrupt (default value)
Disable FRAR1/SRAR1 (default value)
Disable FRAR2/SRAR2 (default value)
Disable FRAR3/SRAR3 (default value)
Disable FRAR4/SRAR4