DHU11 asynchronous serial line interface - Revision history

Vaxorcist: /* Implementation */ corrected DHV11 to DHU11

2024-10-21T14:26:41Z

‎Implementation: corrected DHV11 to DHU11

Jnc: New cat scheme

2023-02-19T00:28:35Z

New cat scheme

Jnc: New cat

2022-08-17T13:54:51Z

New cat

Jnc: /* External links */ +manual

2022-01-30T07:54:45Z

‎External links: +manual

Jnc: +imgs

2021-03-28T18:09:46Z

+imgs

Jnc: An OK start

2021-01-01T13:22:23Z

An OK start

New page

The '''DHU11 asynchronous serial line interface''' was a replacement for the [[UNIBUS]] [[DH11 asynchronous serial line interface|DH11]]. It was not programmatically exactly identical to the DH11, but had all the same basic capabilities: it provided 16 [[EIA RS-232 serial line interface|RS-232]] [[asynchronous serial line]]s, and output used [[Direct Memory Access|DMA]].

The reasons for the replacement of the DH11 are not known, but likely the major one was cost: the DH11 consisted of an entire double [[system unit]] [[backplane]], containing multiple cards; the DHU11 was a single card. It had some minor improvements over the DH11 (including a fix for its [[DH11 asynchronous serial line interface#Design flaw|silo problem]]), but they seem not significant enough by themselves to warrant its replacement. They included:

* input used a 256-character [[First-In First-Out buffer|FIFO buffer]] (somewhat larger than the original DH11's 64-character one);
* the DHU11 includes several [[microprocessor]]s, and has extended capabilities, including a [[diagnostic]] self-test, and [[flow control]] support;
* the DHU11 has the ability to transmit under program control; each line has a 64-character FIFO output buffer.

==Implementation==

Physically, the DHV11 consisted of a single [[DEC card form factor|hex]] card, the M3105, which plugged into a [[Modified UNIBUS Device|MUD]] slot. It connected to a pair of H3029 distribution panels (8 lines each) via BC05L [[flat cable]]s, two per distribution panel; the BC05L connects to a 40-pin [[Berg connector|Berg header]] on each end. The H3029 contains eight male [[EIA RS-232 serial line interface#Connectors|DB-25 connectors]] (DB-25P).

==Device registers==

The [[register]]s in the DHU11 are somewhat different from those in the DH11:

* it was intended to be [[program compatible]] with its [[QBUS]] equivalents (the [[DHV11 asynchronous serial line interface|DHV11]]; and later the [[DHQ11 asynchronous serial line interface|DHQ11]], which could be set to exactly emulate the DHU11), and since the QBUS has a larger [[address space]] than the UNIBUS, it needed two [[word]]-sized registers to hold the output buffer [[address]];
* the previously mentioned improvements.

{| border=1
! Register !! Abbreviation !! Address
|-
|Control and Status Register || CSR || 760020
|-
|Receive Buffer Register || RBUF || 760022
|-
|Receive Timer Register* || RXT || 760022
|-
|Line Parameter Register || LPR || 760024
|-
|Transmit FIFO Data Register || TFD || 760026
|-
|Transmit FIFO Size Register* || TFS || 760026
|-
|Line Status Register* || STAT || 760027
|-
|Line Control Register || CTRL || 760030
|-
|Transmit Buffer Address Register Low || TBADL || 760032
|-
|Transmit Buffer Address Register Hi || TBADH || 760034
|-
|Transmit Buffer Count Register || TBCT || 760036
|}

Registers marked with a '*' are byte width; the others are all word-width. The RBUF and RXT share an address, as do the TFD and TFS: the RBUF is read only, and the RXT is write only; the TFD is write only, and the TFS and STAT are read only. The LPR 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 [[address]]es shown are for the first DHU11 in a system; additional ones are normally set to be at 760040, 760060, etc.

===Control and Status Register (CSR)===
{{16bit-header}}
| TXA || TXIE || DF || TDE || colspan=4 | Tx Line || RDA || RXIE || MR || SKIP || colspan=4 | Line
{{16bitoctal-bitout}}

*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 - Receiver Interrupt Enable
*MR - Master Reset
*SKIP - Skip Self-Test
*Line - Select LPR through TBCT

=== Line Parameter Register (LPR)===
{{16bit-header}}
| colspan=4 | TSpeed || colspan=4 | RSpeed || STOP || EVEN || PARE || colspan=2 | CLEN || colspan=2 | DICD || Unused
{{16bitoctal-bitout}}

===Line Status Register (STAT)===
{{16bit-header}}
| DSR || Unused || RI || DCD || CTS || colspan=2 | Unused || DHU || colspan=8 | Not Present
{{16bitoctal-bitout}}

=== Line Control Register (CTRL)===
{{16bit-header}}
| colspan=3 | Unused || RTS || colspan=2 | Unused || DTR || LTYP || colspan=2 | MAINT || FXOFF || OAUTO || BREAK || RXE || IAF || TXA
{{16bitoctal-bitout}}

==Further reading==

* ''DHU11 User Guide'', EK-DHV11-UG-001

[[Category: UNIBUS Serial Interfaces]]

@@ Line 13: / Line 13: @@
 [[Image:H3029DHU11Dist.jpg|250px|thumb|left|H3029 Distribution Panel]]
-Physically, the DHV11 consisted of a single [[DEC card form factor|hex]] card, the M3105, which plugged into a [[Modified UNIBUS Device|MUD]] slot. It connected to a pair of H3029 distribution panels (8 lines each) via BC05L [[flat cable]]s, two per distribution panel; the BC05L connects to a 40-pin [[Berg connector|Berg header]] on each end. The H3029 contains eight male [[EIA RS-232 serial line interface#Connectors|DB-25 connectors]] (DB-25P).
+Physically, the DHU11 consisted of a single [[DEC card form factor|hex]] card, the M3105, which plugged into a [[Modified UNIBUS Device|MUD]] slot. It connected to a pair of H3029 distribution panels (8 lines each) via BC05L [[flat cable]]s, two per distribution panel; the BC05L connects to a 40-pin [[Berg connector|Berg header]] on each end. The H3029 contains eight male [[EIA RS-232 serial line interface#Connectors|DB-25 connectors]] (DB-25P).
 ==Device registers==

← Older revision		Revision as of 00:28, 19 February 2023
Line 92:		Line 92:
	* [http://www.bitsavers.org/pdf/dec/unibus/EK-DHU11-UG-002_DHU11_Interface_Users_Guide_Nov86.pdf DHU11 User Guide] (EK-DHU11-UG-002)		* [http://www.bitsavers.org/pdf/dec/unibus/EK-DHU11-UG-002_DHU11_Interface_Users_Guide_Nov86.pdf DHU11 User Guide] (EK-DHU11-UG-002)

−	[[Category: UNIBUS ~~Serial Interfaces]]~~	+	[[Category: UNIBUS Asynchronous Serial Interfaces]]
−	~~[[Category: DEC~~ Asynchronous Serial Interfaces]]

← Older revision		Revision as of 13:54, 17 August 2022
Line 93:		Line 93:

	[[Category: UNIBUS Serial Interfaces]]		[[Category: UNIBUS Serial Interfaces]]
		+	[[Category: DEC Asynchronous Serial Interfaces]]

@@ Line 1: / Line 1: @@
 [[Image:DHU11.jpg|350px|thumb|right|DHU11 M3105 board]]
-The '''DHU11 asynchronous serial line interface''' was a replacement for the [[UNIBUS]] [[DH11 asynchronous serial line interface|DH11]]. It was not programmatically exactly identical to the DH11, but had all the same basic capabilities: it provided 16 [[EIA RS-232 serial line interface|RS-232]] [[asynchronous serial line]]s, and output used [[Direct Memory Access|DMA]].
+The '''DHU11 asynchronous serial line interface''' was a replacement for the [[UNIBUS]] [[DH11 asynchronous serial line interface|DH11]]. It was not programmatically exactly identical to the DH11, but had all the same basic capabilities: it provided 16 [[EIA RS-232 serial line interface|RS-232]] [[asynchronous serial line]]s, and used [[Direct Memory Access|DMA]] on the output side.
 The reasons for the replacement of the DH11 are not known, but likely the major one was cost: the DH11 consisted of an entire double [[system unit]] [[backplane]], containing multiple cards; the DHU11 was a single card. It had some minor improvements over the DH11 (including a fix for its [[DH11 asynchronous serial line interface#Design flaw|silo problem]]), but they seem not significant enough by themselves to warrant its replacement. They included:
@@ Line 85: / Line 85: @@
 ==Further reading==
-* ''DHU11 User Guide'', EK-DHV11-UG-001
+* ''DHU11 Technical Manual '', EK-DHU11-TM-001 (not yet online - it's bound, so a copy may have to be sacrificed to scan it)
 [[Category: UNIBUS Serial Interfaces]]