Difference between revisions of "DHV11 asynchronous serial line interface"

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The '''DHV11 asynchronous serial line interface''' is the first [[QBUS]] equivalent to the [[UNIBUS]] [[DH11 asynchronous serial line interface|DH11]] (it was later replaced by the [[DHQ11 asynchronous serial line interface|DHQ11]]). It provided 8 [[EIA RS-232 serial line interface|RS-232]] [[asynchronous serial line]]s. Output used [[Direct Memory Access|DMA]] (with each line having its own [[buffer]] [[pointer]] and count); input used a 256-character [[First-In First-Out buffer|FIFO buffer]].
+
[[Image:DHV11.jpg|350px|thumb|right|DHV11 M3104 board]]
  
==Implementation==
+
The '''DHV11 asynchronous serial line interface''' is the first [[QBUS]] equivalent to the [[UNIBUS]] [[DH11 asynchronous serial line interface|DH11]]. It provided 8 [[EIA RS-232 serial line interface|RS-232]] [[asynchronous serial line]]s, with full [[modem]] control, depending on the cabling option chosen (below). Output used [[Direct Memory Access|DMA]] (with each line having its own [[buffer]] [[pointer]] and count); input used a 256-character [[First-In First-Out buffer|FIFO buffer]].
  
Physically, the DHV11 consisted of a single [[DEC card form factor|quad]] card, the M3104, connected to a pair of H3173-A distribution panels (4 lines each) via a BC05L [[flat cable]], one per distribution panel; the BC05L connects to a 40-pin [[Berg connector|Berg header]] on each end. The H3173-A can be recognized by the [[DEC part number]] 50-15588-01 or -02 on its [[printed circuit board|PCB]]; each contains four male [[EIA RS-232 serial line interface#Connectors|DB-25 connectors]] (DB-25P). In addition to the usual '-xx' length indicators on the BC05L cable, it was also available in BC05L-1K (21 inch) and BC05L-2F (30 inch) lengths.
+
It was later replaced by the [[DHQ11 asynchronous serial line interface|DHQ11]], which could be set to exactly [[program compatible|emulate]] either the DHV11 or the [[DHU11 asynchronous serial line interface|DHU11]].
  
 
==Device registers==
 
==Device registers==
  
The [[register]]s in the DHQ11 are somewhat different from those in the DH11:
+
The [[register]]s in the DHV11 are somewhat different from those in the DH11:
  
 
* the QBUS has a larger [[address space]] than the UNIBUS, so it needs two [[word]]-sized registers to hold the output buffer [[address]];
 
* the QBUS has a larger [[address space]] than the UNIBUS, so it needs two [[word]]-sized registers to hold the output buffer [[address]];
* the DHQ11 includes several [[microprocessor]]s, and has extended capabilities, including a [[diagnostic]] sealf-test, and [[flow control]] support;
+
* the DHV11 includes several [[microprocessor]]s, and has extended capabilities, including a [[diagnostic]] self-test, and [[hardware]] in-band [[flow control]] support (on both input and output);
* the DHQ11 has the ability to transmit under program control.
+
* the DHV11 has the ability to transmit under program data movement.
  
 
{| border=1
 
{| border=1
Line 34: Line 34:
 
|Transmit Buffer Count Register        || TBCT || 17760456
 
|Transmit Buffer Count Register        || TBCT || 17760456
 
|}
 
|}
 +
 +
[[Image:M3104.jpg|150px|left|thumb|Another DHV11 board]]
  
 
The RBUF and TXC share an address; the RBUF is read only, and the TXC is write only.  
 
The RBUF and TXC share an address; the RBUF is read only, and the TXC is write only.  
Line 53: Line 55:
 
*RXIE - Receive Interrupt Enable
 
*RXIE - Receive Interrupt Enable
 
*MR - Master Reset
 
*MR - Master Reset
*Line - Select TXC through TBCT
+
*Line - Select line register set (TXC through TBCT)
  
 
=== Line Parameter Register (LPR)===
 
=== Line Parameter Register (LPR)===
Line 59: Line 61:
 
| colspan=4 | TSpeed || colspan=4 | RSpeed || STOP || EVEN || PARE || colspan=2 | CLEN || colspan=2 | DICD || Unused
 
| colspan=4 | TSpeed || colspan=4 | RSpeed || STOP || EVEN || PARE || colspan=2 | CLEN || colspan=2 | DICD || Unused
 
{{16bitoctal-bitout}}
 
{{16bitoctal-bitout}}
 +
 +
*DICD - Diagnostic Code
 +
**00 - Normal operation
 +
**01 - Report status via the FIFO
  
 
===Line Status Register (STAT)===
 
===Line Status Register (STAT)===
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| DSR || Unused || RI || DCD || CTS || colspan=2 | Unused || DHU || colspan=8 | Not Present
 
| DSR || Unused || RI || DCD || CTS || colspan=2 | Unused || DHU || colspan=8 | Not Present
 
{{16bitoctal-bitout}}
 
{{16bitoctal-bitout}}
 +
 +
*DHU - DHU indication (always '0')
  
 
=== Line Control Register (CTRL)===
 
=== Line Control Register (CTRL)===
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{{16bitoctal-bitout}}
 
{{16bitoctal-bitout}}
  
==Further reading==
+
*LTYP - Link Type
 +
*MAINT - Maintenance Mode
 +
**00 - Normal operation
 +
**01 - Automatic echo mode
 +
**10 - Local loopback
 +
**11 - Remote loopback
 +
*FXOFF - Force XOFF (on incoming traffic)
 +
*OAUTO - Outgoing Auto-Flow (flow control)
 +
*BREAK - Transmit Break
 +
*RXE - Receiver Enable
 +
*IAF - Incoming Auto-Flow (flow control)
 +
*TXA - Transmit DMA Abort
 +
 
 +
==Implementation==
 +
 
 +
Physically, the DHV11 consisted of a single [[DEC card form factor|quad]] card, the M3104. It uses four Dual [[Universal Asynchronous Receiver/Transmitter|UART]] (DUART) [[integrated circuit|chips]], and connects to one or two [[distribution panel]]s via [[flat cable]]s plugged into [[Berg connector|Berg headers]] on edge of the  card.
 +
 
 +
===Cabling===
 +
 
 +
There are two options for cabling to the DHV11; the first (usual) one provides full modem control, the second carries no modem control [[signal]]s, and is thus only suitable for local terminals.
 +
 
 +
In the former, the DHV11 is connected to a pair of H3173-A distribution panels (4 lines each) via a BC05L flat cable, one per distribution panel; the BC05L connects to a 40-pin Berg header on each end. The H3173-A  contains four male [[EIA RS-232 serial line interface#Connectors|DB-25 connectors]] (DB-25P), i.e. wired as DTEs (most local terminals will therefore require a a [[EIA RS-232 serial line interface|null modem]]).
 +
 
 +
It can be recognized by the [[DEC part number]] 50-15588-01 or -02 on its [[printed circuit board|PCB]]; the two versions differ in their layout, but have identical functionality, and are interchangeable. In addition to the usual '-xx' length indicators on the BC05L cable, it was also available in BC05L-1K (21 inch) and BC05L-2F (30 inch) lengths.
 +
 
 +
The alternative approach is the "remote distribution panel cabinet kit". In this, an intermediate "bulkhead panel" (H3176, PCB part number 50-16805) containing a single DB-25S female connector (''not'' wired as an EIA port) is connected to the DHV11 via the usual flat cables; this is then connected externally via a BC22H 25-[[conductor]] external round cable to a "remote distribution panel" (H3175), which contains eight DB-25P male connectors (likely wired as DTEs, but the DEC documentation does not say so explicitly).
 +
 
 +
==See also==
 +
 
 +
* [[DLV11-J asynchronous serial line interface]]
 +
* [[DZV11 asynchronous serial line interface]]
 +
<!-- ==Further reading==
 +
 
 +
*
 +
-->
 +
==External links==
  
* ''DHV11 Technical Manual'', EK-DHV11-TM-001
+
* [http://www.bitsavers.org/pdf/dec/qbus/EK-DHV11-TM-002.pdf DHV11 Technical Manual] (EK-DHV11-TM-002)
 +
* [http://www.vaxhaven.com/images/6/6b/EK-DHV11-MC.pdf DHV11 Maintenance Card] (EK-DHV11-MC)
 +
* [https://manx-docs.org/collections/hcps/dhv11.pdf DHV11 Field Maintenance Print Set] (MP01793)
  
 
[[Category: QBUS Serial Interfaces]]
 
[[Category: QBUS Serial Interfaces]]

Latest revision as of 16:58, 2 February 2022

DHV11 M3104 board

The DHV11 asynchronous serial line interface is the first QBUS equivalent to the UNIBUS DH11. It provided 8 RS-232 asynchronous serial lines, with full modem control, depending on the cabling option chosen (below). Output used DMA (with each line having its own buffer pointer and count); input used a 256-character FIFO buffer.

It was later replaced by the DHQ11, which could be set to exactly emulate either the DHV11 or the DHU11.

Device registers

The registers in the DHV11 are somewhat different from those in the DH11:

  • the QBUS has a larger address space than the UNIBUS, so it needs two word-sized registers to hold the output buffer address;
  • the DHV11 includes several microprocessors, and has extended capabilities, including a diagnostic self-test, and hardware in-band flow control support (on both input and output);
  • the DHV11 has the ability to transmit under program data movement.
Register Abbreviation Address
Control and Status Register CSR 17760440
Receive Buffer Register RBUF 17760442
Transmit Character Register TXC 17760442
Line Parameter Register LPR 17760444
Line Status Register STAT 17760446
Line Control Register CTRL 17760450
Transmit Buffer Address Register Low TBADL 17760452
Transmit Buffer Address Register Hi TBADH 17760454
Transmit Buffer Count Register TBCT 17760456
Another DHV11 board

The RBUF and TXC share an address; the RBUF is read only, and the TXC is write only. The TXC through TBCT are replicated, with one for each line in the device; the 'Line' field in the CSR indicates which one is currently available.

The addresses shown are for the first DHV11 in a system; additional ones are normally set to be at 17760460, 17760500.

Control and Status Register (CSR)

TXA TXIE DF TDE Unused Tx Line RDA RXIE MR Unused Line
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
  • TXA - Transmitter Action
  • TXIE - Transmit Interrupt Enable
  • DF - Diagnostic Fail
  • TDE - Transmit DMA Error
  • Tx Line - Line which set TXA
  • RDA - Received Data Available
  • RXIE - Receive Interrupt Enable
  • MR - Master Reset
  • Line - Select line register set (TXC through TBCT)

Line Parameter Register (LPR)

TSpeed RSpeed STOP EVEN PARE CLEN DICD Unused
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
  • DICD - Diagnostic Code
    • 00 - Normal operation
    • 01 - Report status via the FIFO

Line Status Register (STAT)

DSR Unused RI DCD CTS Unused DHU Not Present
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
  • DHU - DHU indication (always '0')

Line Control Register (CTRL)

Unused RTS Unused DTR LTYP MAINT FXOFF OAUTO BREAK RXE IAF TXA
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
  • LTYP - Link Type
  • MAINT - Maintenance Mode
    • 00 - Normal operation
    • 01 - Automatic echo mode
    • 10 - Local loopback
    • 11 - Remote loopback
  • FXOFF - Force XOFF (on incoming traffic)
  • OAUTO - Outgoing Auto-Flow (flow control)
  • BREAK - Transmit Break
  • RXE - Receiver Enable
  • IAF - Incoming Auto-Flow (flow control)
  • TXA - Transmit DMA Abort

Implementation

Physically, the DHV11 consisted of a single quad card, the M3104. It uses four Dual UART (DUART) chips, and connects to one or two distribution panels via flat cables plugged into Berg headers on edge of the card.

Cabling

There are two options for cabling to the DHV11; the first (usual) one provides full modem control, the second carries no modem control signals, and is thus only suitable for local terminals.

In the former, the DHV11 is connected to a pair of H3173-A distribution panels (4 lines each) via a BC05L flat cable, one per distribution panel; the BC05L connects to a 40-pin Berg header on each end. The H3173-A contains four male DB-25 connectors (DB-25P), i.e. wired as DTEs (most local terminals will therefore require a a null modem).

It can be recognized by the DEC part number 50-15588-01 or -02 on its PCB; the two versions differ in their layout, but have identical functionality, and are interchangeable. In addition to the usual '-xx' length indicators on the BC05L cable, it was also available in BC05L-1K (21 inch) and BC05L-2F (30 inch) lengths.

The alternative approach is the "remote distribution panel cabinet kit". In this, an intermediate "bulkhead panel" (H3176, PCB part number 50-16805) containing a single DB-25S female connector (not wired as an EIA port) is connected to the DHV11 via the usual flat cables; this is then connected externally via a BC22H 25-conductor external round cable to a "remote distribution panel" (H3175), which contains eight DB-25P male connectors (likely wired as DTEs, but the DEC documentation does not say so explicitly).

See also

External links