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31.1 GENERAL DESCRIPTION . . . . . . . . . . . . . . 31-1
31.2 CAMAC PROTOCOL . . . . . . . . . . . . . . . . . 31-2
31.2.1 Control Block . . . . . . . . . . . . . . . . 31-2
31.2.2 FTP Block . . . . . . . . . . . . . . . . . . 31-2
31.2.3 Status Block . . . . . . . . . . . . . . . . . 31-2
31.2.4 Status Word . . . . . . . . . . . . . . . . . 31-2
31.2.5 Message Word . . . . . . . . . . . . . . . . . 31-3
31.3 TIMING SYSTEM . . . . . . . . . . . . . . . . . 31-3
31.3.1 Idle Trigger . . . . . . . . . . . . . . . . . 31-3
31.3.2 PDU Channel Select . . . . . . . . . . . . . . 31-4
31.3.3 Fast Time Plot . . . . . . . . . . . . . . . . 31-4
31.4 MODULE FUNCTION CODES . . . . . . . . . . . . . 31-5
31.5 HARDWARE . . . . . . . . . . . . . . . . . . . . 31-6
31.5.1 Power Requirements . . . . . . . . . . . . . . 31-6
31.5.2 Temperature Limits . . . . . . . . . . . . . . 31-6
31.5.3 Package . . . . . . . . . . . . . . . . . . . 31-6
31.5.4 DataLink Cable . . . . . . . . . . . . . . . . 31-6
31.5.5 Front Panel . . . . . . . . . . . . . . . . . 31-7
31.6 DRAWING PACKAGE NUMBER . . . . . . . . . . . . . 31-8
31.7 RESPONSIBLE ENGINEERS . . . . . . . . . . . . . 31-8 CHAPTER 31 PARALLEL INPUT/OUTPUT PROCESSOR (PIOP)
31.1 GENERAL DESCRIPTION The PIOP is a general purpose CAMAC module which is controlled by an internal 8088 microprocessor. The PIOP will be programmed to meet the requirements of the MK-2 Modulator Klystron Support, Phase and Amplitude Detection, and Sub-Booster instrumentation. The PIOP has 256 channels of DataLink I/O capability through the front panel connector. The module uses the standard SLC 18 pair data cable with differential TTL logic. The microprocessor and CAMAC share a block of memory which is used for transfering data, status, and control information. There are three blocks of data and two words available for general use. They are usually configured as follows: o The CTL_Block is used to write operational parameters to the PIOP from CAMAC. It is typically 16 words deep, and has a rigid format described later. o The STATUS_Block is used to describe the current state of the module. The block is typically 32 words deep and has a standard format for the first five words only. o The FTP_Block is used to store data as that received from a Fast Time Plot type sampling system. Data in the FTP_Block is typically in chronological order, and is stored as 16 bit two's complement integer data. o The Status_Word is a 16 bit word for general use; ie, module status. o The Message_Word is associated with the CAMAC LAM system. It is a 16 bit word used to describe the LAM condition. ______________________________ What follows is a logical subset of the Parrallel Input/Output Processor Hardware Specifications.
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-2 Access to the above blocks and words is controlled by four internal status flags.
31.2 CAMAC PROTOCOL
31.2.1 Control Block The Control Block is a block of memory which is used by the control system to load commands to the PIOP. The control block consists of a control word, data words, checksum word, and undefined words to fill the block with 16 words. The format of each block is determined by the control word.
31.2.2 FTP Block The Fast Time Plot Block is used for downloading a program for the local micro, and for storage of FTP data points for the FTP channel selected through the control block. The length of the FTP block is 67 words, (or 134 bytes). The FTP will typically contain a 3 word header followed by 64 data points in chronological order from the channel selected.
31.2.3 Status Block By convention, the Status Block contains recent values of many of the operational parameters used by the micro. The Status Block is updated in memory, and the starting address of the block is moved to point to the new block, insuring that all entries are matched to the same set. The length of the Status Block is 32 words long. Due to the nature of the asynchronous updating of the status block, there is a real and small "collision" probability on CAMAC reads of the block. The collision rate is less then one percent, and is detected by invalid Q response from the PIOP.
31.2.4 Status Word The Status word is a 16 bit word that is readable through a single CAMAC call. The Status word is updated by the local micro at trigger rate, and contains the status of the system as of the last update. Reading the Status Word before the local micro updates the word after the last read, or while the micro updates the word will result in Q = 0.
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-3 There are no restrictions on the contents or meaning of the 16 bit status word with the following note: The Status Word will be read as 0000H when the Dead Man Timeout is set, and should therefore not be coded as "OK-OK".
31.2.5 Message Word The Message word is a 16 bit word that is readable through a single CAMAC call. The Message word is updated by the local micro, and the flag STFG_4 is set, generating a LAM, if enabled. Reading the Message word clears the LAM. Note that the Dead Man Time-Out circuit sets DMTO, which fires a LAM, if enabled. All CAMAC reads while DMTO is set will be '00'X. The Message word '00'X is reserved for DMTO. The Message words are defined for SLC applications in the following locations: o SLCRMX:PIOPFUNC.INC o REF_RMX_KLYS:PIOPERRSE.F86 o SLCPIOP:PIOPERROR.INC The last reference is intended to be included in the piop software.
31.3 TIMING SYSTEM The PIOP has the ability of selecting a channel from the PDU driven upper backplane connector on the CAMAC crate. The PIOP has in addition to the selected channel, a hard wired IDLE-TRIGger option. The selected channel is the MOD-TRIGger. The IDLE-TRIG is used to fire a klystron at a constant rate in the absence of the MOD-TRIG. This may occur when the pattern is not transmitted. The selected trigger is stretched to 800 nano-seconds and (if enabled) is passed out to the DataLink connector (M-Trig).
31.3.1 Idle Trigger The Idle Trigger fires the type 18H interrupt of the microprocessor and may be used for alternate triggers (ie - for klystrons). The Type 18H interrupt must be re-armed by a read from the TRIG_REG (Location 5816) after each interrupt.
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-4
31.3.2 PDU Channel Select The PIOP can select the MOD-TRIG from any of the first 8 channels. The IDLE-TRIG is assigned to channel 0.
31.3.3 Fast Time Plot The Fast Time Plot is a diagnostic tool which resembles a sampling oscilloscope. Samples are taken following separate triggers until 64 samples are accumulated. The sample time is varied with fixed step size, and the results are read from CAMAC for display by the operating system. The PIOP receives a 119.0 MHz system clock on the upper backplane connector. A 14.875 MHz clock is derived from the system clock (119/8) which is used as the timebase for the FTP. The 14.875 MHz is interrupted once each trigger to allow the divide by eight circuits to synchronize the clock with the incoming trigger. This clock is provided on the front panel DataLink connector. The support package (the MK-2 for example) will have a presettable counter to generate the FPT sample time as a delayed trigger. The sample step size and starting delay are N * 33.6134 nanoseconds.
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-5
31.4 MODULE FUNCTION CODES The CAMAC functions accepted by the PIOP are as follows: Function Block Description Q Code Length* Response ---------------------------------------------------------- F0*A0 16w Read CTL_BLOCK Q=/END * STFG_1 F0*A1 67w Read FTP_BLOCK Q=/END * STFG_2 F0*A2 32w Read STATUS_BLOCK Q=/END * DMA-AVAILABLE F2*A2 1w Read Status Word Q=STFG_3 F2*A3 1w Read MessageWord (clrs LAM) Q=LAM_STATUS F11*A0 Set Start CTL_BLOCK Q=1 F11*A1 Set Start FTP_BLOCK Q=1 F11*A2 Set Start STATUS_BLOCK Q=1 F16*A0 16w Write CTL_BLOCK Q=/END * STFG_1 F16*A1 67w Write FTP Block Q=/END * STFG_2 F19*A8 1w Write PPYY Broadcast Q=X=0 F8*A3 Test LAM Q=LAM F10*A3 Clear LAM (clrs LAM) Q=0 F24*A3 Disable LAM (clrs LAM_ENB) Q=0 F26*A3 Enable LAM (sets LAM_ENB) Q=0 F27*A3 Test LAM Status Q=LAM_STATUS F25*A0 Reset Local Micro Q=0 (Including LAM_ENB) ______________________________ (*) The size of the Control Block, the Fast Time Plot block , and the Status Block are controlled by the resident local micro software. Typical sizes are indicated. It is proposed to use the FTP block for downloading of the local micro program, and the size of the block for this operation need not be the same as for FTP use. ______________________________ For blocks where Q is specified as Q=/END, the CAMAC read or write should "scan" until Q=0, or termination of byte count. Byte count should always be 2 * block length on complete transfers. Note that LAM is: LAM = LAM_ENB * LAM_STATUS. LAM_STATUS is STFG_4 or DMTO (dead man time-out). The STFG_4 and DMTO are both cleared by the local micro, or a F2*A3, a F10*A3, a F25*A0, or a Z from CAMAC. The qualifiers on the Q response are required to insure that blocks are not overwritten too soon and so the read data will be block-wise consistent.
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-6 STFG_1 and STFG_2 control access such that the blocks are recent and contiguous. Under normal CAMAC operations, these flags should be transparent. STFG_3 and DMA Available are denied for short periods of time to allow the asynchronious updating of the word or buffer. The "collision" probability is << one percent between the micro and CAMAC.
31.5.1 Power Requirements The CAMAC power requirement of the PIOP are: o 1.80 Amps of +6 Volts. o 0.18 Amps of -6 Volts. Additionally, a small amount of -2 Volts is used from the SLC Upper Backplane, where equipted.
31.5.2 Temperature Limits The PIOP is designed to work in the SLAC klystron gallery environment of 0 C to +65 C and noncondensing humidity.
31.5.3 Package The PIOP is a single width CAMAC module which uses the standard CAMAC backplane and the upper backplane for timing signals from the PDU.
31.5.4 DataLink Cable The data cable is the SLC standard 18 pair shielded cable. o DataLink Cable Length The maximum length of the data cable is 300 feet. o DataLink Cable Type The cable is fully documented in the Scanning Analog Monitor documentation. The cable prints are: > CA-123-603-01
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-7 > CA-123-603-02 > WL-123-603-03
31.5.5 Front Panel The Front panel of the PIOP has the following:
18.104.22.168 Front Panel Lights - The PIOP has two classes of front panel lights: o A set of five lights indicating (for example) station ID. o A light which flashes when "N" is asserted.
22.214.171.124 Front Panel DataLink - The DataLink has the following special attributes: o Connector -- 36 pin AMP connector. o Signal Levels -- EIA Standard RS-422 Differential TTL, terminated with 100 Ohms. o DataLink Cable Pin Assignments: Pair TRUE COMP. SIGNAL ---- ---- ----- ------ 1 A1 A2 Data Bit 0 2 A3 A4 Data Bit 1 3 A5 A6 Data Bit 2 4 A7 A8 Data Bit 3 5 A9 A10 Data Bit 4 6 A11 A12 Data Bit 5 7 B1 B2 Data Bit 6 8 B3 B4 Data Bit 7 9 B5 B6 I/O Read 10 B7 B8 I/O Write 11 B9 B10 ADdress Latch 12 B11 B12 /ACKNowledge 13 C1 C2 M-Trig (800 NS Pulse) 14 C3 C4 Continuous CLocK
PARALLEL INPUT/OUTPUT PROCESSOR (PIOP) Page 31-8 (14.875 MHz) 15 C5 C6 /Head Interrupt (Type 11H) -- C12 -- Shield (ground)
31.6 DRAWING PACKAGE NUMBER 123-624
31.7 RESPONSIBLE ENGINEERS M. Browne / K. Jobe