= HF8V = / = SP8WJT = / = SP0106RZ =

HF-17831


PROJECT: HF-17831
DESCRIPTION: TELETEXT module
MODEL: MS-4101
BRAND: PROELCO
STATUS: u
PROJECT START DATE:
LOCALISATION: PL
DOCUMENTATION: recreated, notebook B8, page 33
PCB: TPD57831

CPU: SDA5250
BRAND: SIEMENS
CPU CATALOG NUMBER: UC-299
CLOCK: 18MHz (pixel clock is divided by 6 for '51 core resulting in 3 MIPS)
ADDRESS SPACE: 512KB
RAM: 256B + 8KB (MOVX, display memory) + 1KB (MOVX, acquisition memory) + 1KB (MOVX, XRAM general purpose)
THN ADR: 0x33
TYPE: 0x53



Project Info

Teletext module from unknown TV set.


CIRCUIT

IC:
  • IC501 - SDA5250 - CPU
  • IC502 - TMS27C010 - EPROM 128KB - MM-215
  • IC503 - 24LC16 - EEPROM 2KB

    • T:
  • T501 - BC547 - base from W040.1/G501.7 via R504, collector to P3.3
  • T502 - BC547 - R output
  • T503 - BC547 - G output
  • T504 - BC547 - B output
  • T505 - BC547 - BLAN output
  • T506 - BC547 - P0.0 output
  • T507 - not soldered
  • T508 - BC557 - P3.5 output
  • T509 - BC557 - P3.4 output
  • T510 - BC547 - input to VS/P4.7

    • CONNECTORS

    G501:
  • 1 - NC
  • 2 - P0.0 (via T506, open collector)
  • 3 - BLAN (via T505)
  • 4 - B (via T504)
  • 5 - G (via T503)
  • 6 - R (via T502)
  • 7 - input to P3.3 (via R504, T501), =W040.1
  • 8 - VS/P4.7 + C314 input (via T510)
  • 9 - P2.2
  • 10 - P2.3
  • 11 - CVBS input (via R503 || C525)

    • G502:
  • 1 - P0.4 (via C, R)
  • 2 - P3.6 (pullup)
  • 3 - I2C_SDA (via 100 ohm + 180 ohm), P1.7 (via 180 ohm)
  • 4 - I2C_SCL (via 100 ohm + 180 ohm), P3.1 (via 180 ohm)
  • 5 - +5V
  • 6 - GND
  • 7 - P3.7 (pullup)
  • 8 - HS/SC input (via R 2.2k)
  • 9 - P3.2 + C 22nF to GND
  • 10 - P0.2 (pullup)
  • 11 - P3.0

    • W010:
  • 1 - GND (modified)
  • 2 - P1.3
  • 3 - P1.4
  • 4 - P1.5
  • 5 - P1.6

    • W040:
  • 1 - input, to P3.3 (via R504, T501), =G501.7
  • 2 - GND
  • 3 - +5V
  • 4 - P3.4 (output via T509)
  • 5 - P3.5 (output via T508)
  • 6 - NC

    • W501:
  • 1 - GND
  • 2 - P2.0 (pullup)

    • W502: (not soldered)
  • 1 - P0.5
  • 2 - P0.6
  • 3 - +5V



    • MEMORY MAPPING

    Memory range: 128KB
    Processor can choose to jump to either low or high 64K memory segment...

    ADRP1.0 -> (A16)REMARKS
    0x00000 - 0x0FFFF0
    0x10000 - 0x1FFFF1RESET should be here...

    CPU lines A16-A18 not soldered (can be extended to 512K).
    Interesting why P1.0 was used instead of A16 but maybe code disassembly and analyze will answer this question...


    MODIFICATIONS
    1/ XTAL 18 MHz changed to 17.774 MHz (I nedeed XTAL 18 MHz to another project).
    2/ Original G501, G502 connectors desoldered and changed to GOLDPIN.
    3/ EPROM 27C010 changed to flash 128KB.
    4/ XTAL changed to 27 MHz (see testing).


    TESTING/OVERCLOCKING EXPERIMENTS
    1/ Tested with W49F002 flash. I needed remove Z516 jumper and ground IC502.A16 because test program is at 0x00000 location.
    All seems work OK. PORT1 is keyed with fCLK/36 what is typical for SDA5250 (same achived for HF-1774).
    2/ Tested with XTAL 25 MHz. PORT1 switching works OK. No idea about other peripherials.
    3/ Tested with XTAL 27 MHz. PORT1 switching works OK. No idea about other peripherials.
    4/ Tested with XTAL 30 MHz. PORT1 switching works OK. No idea about other peripherials. ALE signal = 10MHz.
    5/ Tested with XTAL 35.975 MHz. C503, C504 changed to 10pF. Works unstable (sometimes work, sometimes not). Flash speed grade is 120ns. So...
    6/ Returning to 30 MHz XTAL. C503, C504 changed to 22pF
    7/ Again unstable work appeared. It must be flash timing specification, because ALE signal is stable at 10 MHz. Changed XTAL to 27 MHz.
    Now works stable even if it is still little bit beyond specification (ALE 111ns). If think it can still be overcloked with higher speed flash.

    There is also similiar SDA5250 teletext module registered as HF-1774

    8-byte test program

    This is the simplest '51 machine test code which can be inserted manually byte-by-byte into memory (ROM, RAM or flash). I'm using this to test if uC from unknown source is still alive...
    PORT1 must be tested with fq meter, oscilloscope or communication receiver (latter is typical Amateur Radio way cos you can also hear clock and its quality).
    On SDA5250 I got 500 kHz frequency what is fCLK/36.

    ADRCODEMNEMONIC
    0000: 75 90 00 MOV PORT1, #0x00
    0003: 75 90 FF MOV PORT1, #0xFF
    0006: 01 00 SJMP 0x0000


    Sources:
    [1] - SDA5250 datasheet


    Prefix 17

    HF Register

    Microcontrollers in my constructions

    UC Database - my CPU collection

    Electronics

    Main Page