The SLAC reserved locations in DM are listed below (see SLAC MK/II FASTBUS NOTE #9).
SLAC MKII SSP Data Memory reserved locations
______________________________________________________ | SSP DM | | | byte | Contents | | address | | | (hex) | | |------------|----------------------------------------| | 00 | Initial PSW and error PSW | | 04 | Updated Memory address register (MAR) | | 08 | Error PSW | | 0C | Interrupt handler address (if >0) | | 10 | Error return address (if > 0) | | 14 | Original PSW | | 18 | Error handler return code | | 1C | Program done flag | | 20 | HALT data (for WCSR0) | | 24 | Error handler control word | | 28 | 6 words user defined | | 40 | Register dump area (16 words) | | 80 | Total entries to error handler | | 84 | Total divide-by-zero errors | | 88 | Total overflow errors | | 8C | Total unsupported opcodes | | 90 | Total block-count-exhausted | | 94 | Total I/O errors: arbitration | | 98 | Total I/O errors: address | | 9C | Total I/O errors: data | | A0 | 7 words reserved for error handler | | BC | Total external interrupts | | C0 | No. times SSP IPLed at PM80 | | C4 | PM location of most recent halt | | C8 | 13 words reserved | | FC | reserved for HALT macro | | 100 | reserved for SNOOPY debugger (16 words)| | 140 | SSP interrupt control block (16 words) | | 180 | SSP interrupt message block (16 words) | ______________________________________________________
Reserved locations in DM for the BNL system are shown here. See 787DOC:SSP_PROGRAMMER.MEM for more details.
________________________________________________________ | SSP Data | | | memory | Contents | | address | | | (hex) | | |------------|-------------------------------------------| | 00 | SSP starting PSW | | 04 | Updated MAR | | 08 | Saved error or interrupt PSW. | | 10 | User-specified error-return address. | | 18 | Error code | | 1C | Halt code | | 20 | Datum for the HALT instruction. | | 2C | Datum for the PAUSE instruction. | | 30 | Current contents of register 13 | | 3C | The number of DM words in this SSP. | | 40 | Register dump area (16 words) | | 80 | Total errors counter | | 84 | Divide-by-zero errors | | 88 | Overflow errors | | 8C | Unsupported opcodes | | 90 | Block-count-exhausted | | 94 | Arbitration time-outs | | 98 | Primary address time-outs | | 9C | I/O cycle time-outs | | A0 | Wrap-around errors | | A4 | Unknown time-outs | | A8 | Slave busy (SS=1) errors | | AC | Slave done (SS=2) errors | | B0 | SS=3,4,5 (unknown code) | | B4 | Slave data errors (SS=6,7) | | B8 | Unknown Fastbus errors | | C4 | Address of instruction following last | | CC | Word-address of lowest free PM word. | | D4 | Lowest free DM location | | D8 | Highest free DM location | | E0 | 4 words reserved for breakpoint | | F0 | BSI DM base address | | F4 | BSI PM system start address. | | F8 | System save register area (6 words) | | 140 | Reserved 16 words (internal control block)| | 180 | Reserved 16 words (internal message block)| | 1C0 | PA of SSP on the crate segment | | 1C4 | PA of SSP on the cable segment | | 1C8 | Reserved until DM200 | ________________________________________________________