Samsung SDC-30 Service Manual page 10

2-1-6 Sytem control
Dual controller (MICOM) is located in DSC : A RISC chip controls the signal processing, and is the 4-bit MICOM
controls the LCD, timer, and switch.
1. 4-bit MICOM; Functions and connections
1) PIN connection status
- RISC is connected to the 4-bit MICOM (total 7 lines).
- Pins 98, 130, and 108 and SCI No. 1 are used.
- Pins 132, 133, 134, and 136 are used for communication with 4-bit MICOM.
- Synchronized communication is used with 4-bit MICOM.
2) Function
- RISC is usally in the standby mode (low-power) because it consumes so much current when it operates.
- 4-bit MICOM acknowledges the starting time (for example, when the user pushes the shot key) and sends the
NMI pin signal to RISC, so that the standby mode can be changed to the operation mode. The information is
sent to RISC through communication port. After RISC executes the appropriate program, it returns to the
standby mode.
2. Main function of 4-bit MICOM
- Power ON/OFF: 4-bit MICOM turns the PC (main body) on, and turns on the RISC.
- Execution of shot: When the shot is executed by the PC key (or main body), 4-bit MICOM signals the shot
execution to RISC. When the shot is finished (system 5V and head power 5V), 4-bit MICOM changes the RISC
mode to standby mode.
- Delay shot: When the delay shot is executed by the PC key (or main body), 4-bit MICOM signals the RISC and
supplies the system 5V and head power 5V. Then, the RISC changes to standby mode.
Samsung Electronics
Fig. 2-7
Reference Information
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