DZ11 asynchronous serial line interface
The DZ11 was a UNIBUS 8 port asynchronous serial line mux card for DEC computers. It used used programmed I/O, and thus could present a considerable load on the CPU when running a high speed line. A 64-entry FIFO buffer silo was provided on the input side.
Both EIA and 20mA physical layers were supported; the EIA model could operate with full-duplex modems. It provided program-set baud rates (up to 9600 baud), but not split speed. Break could be detected or generated on each line.
Contents
Implementation
Physically, it was a hex card, which plugged into an SPC backplane slot. The EIA version was the M7819, and the 20mA one was the M7814. On the M7819, a flat cable led from a Berg connector on the card via a static filter to an H317-E EIA distribution panel, holding 16 DB25 male connectors (DB-25P) wired as DTEs, enough for two DZ11 cards.
Accessories for the EIA version are:
- BC05W-15 50 conductor signal cable
- H7004C Static Filter
- BC06L-0J 50 conductor signal cable
- H317-E EIA distribution panel
- Cable Box assembly
- H325 test connector (single line)
- H3271 staggered test connector
The later H3006 distribution panel for the EIA version was part of DEC's modular back-panel system.
For the 20mA, substitute the:
- BC08S-15 40 conductor signal cable
- H7004B Static Filter
- BC06K-0J 40 conductor signal cable
- H317-F 20mA distribution panel
- H3190 staggered test connector.
Device registers
| Register | Abbreviation | Address |
|---|---|---|
| Control and Status Register | CSR | 760100 |
| Receiver Buffer Register* | RBUF | 760102 |
| Line Parameter Register* | LPR | 760102 |
| Transmit Control Register | TCR | 760104 |
| Modem Status Register | MSR | 760106 |
| Transmit Data Register | TDR | 760106 |
The RBUF and LPR share an address, as do the MSR and TDR: the RBUF is read only, and the LPR is write only; the MSR is read only, and the TDR is write only. Registers marked with a '*' are word-width only, no byte operations.
The addresses shown are for the first DZ11 in a system (provided that there are no other devices in the floating device address space); additional ones are normally set to be at 760110, 760120, etc.
Control and Status Register (CSR)
| TRDY | TIE | SA | SAE | Unused | Tx Line | RDONE | RIE | MSE | CLR | MAINT | Unused | ||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
- TRDY - Transmitter Ready
- TIE - Transmitter Interrupt Enable
- SA - Silo Alarm
- SAE - Silo Alarm Enable
- Tx Line - Line ready to transmit
- RDONE - Received Done
- RIE - Receiver Interrupt Enable
- MSE - Master Scan Enable
- CLR - Clear input FIFO, CSR and UARTs
- MAINT - Maintenance loopback enabled
Receiver Buffer Register (RBUF)
| DV | OVR | FRERR | PERR | Unused | Rx Line | RBUF | |||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
Line Parameter Register (LPR)
| Unused | RXON | Speed | ODDP | PAREN | STOP | CLEN | Line | ||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
Transmit Control Register (TCR)
| DTR | Line Enabled | ||||||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
Modem Status Register (MSR)
| CD | RI | ||||||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
Transmit Data Register (TDR)
| Break | TBUF | ||||||||||||||
| 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
Further reading
- DZ11 User Guide, EK-DZ11-UG-002
- DZ11 Maintenance Manual, EK-DZ11-MM-001
