= HF8V = / = SP8WJT = / = SP0106RZ =
HF-1774
PROJECT: HF-1774
DESCRIPTION: Teletext module
BRAND: ?
PCB INFO: 29304-792.37/38(01)
DIMENSIONS: 82 x 59 mm
STATUS: u
PROJECT START DATE:
LOCALISATION: PL
DOCUMENTATION: TM, recreated
PCB: TPD57074
CPU : SDA5250
CPU BRAND: SIEMENS
CPU CATALOG NUMBER: UC-298
CLOCK: 18 MHz (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: 0x32
TYPE: 0x53
Documentation recreated, tested, original software downloaded.
I changed original memory socket from 64KB DIP28 chip (original memory was EPROM 27C512) to DIP32 memory and installed 256KB flash W49F002,
what is very convinient if you want develop new soft... This uC have even bigger addressing capacity, namely 512KB, but 256KB is big enough,
so I'm happy with it at the moment... Tested with 8 byte test program (programmed into flash manually in machine code from HF-6030), all works OK.
Some kind of system will be developed later, this uC have interesting capabilities with OSD, what can be used as simple text/graphic card.
There is also similiar SDA5250 teletext module registered as HF-17831
Element Base
IC:
IC80905 - SDA5250 - CPU
IC80920 - 27C512 - EPROM 64KB
8-byte test program
This is simple '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.
| ADR | CODE | MNEMONIC |
|---|
| 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
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