NEC mPD780852 Series, Preliminary User'S Manual

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CHAPTER 16 LCD CONTROLLER/DRIVER
Preliminary User’s Manual U14581EJ3V0UM00
16.9 Cautions on Emulation
(1) LCD timer control register (LCDTM)
To perform debugging with an in-circuit emulator (IE-78K0-NS), the LCD timer control register (LCDTM) must
be set. LCDTM is a register used to set a probe board (IE-780852-NS-EM4).
LCDTM is a write-only register that controls supply of the LCD clock. Unless LCDTM is set, the LCD controller/
driver does not operate. Therefore, set bit 1 (TMC21) of LCDTM to 1 when using the LCD controller/driver.
Figure 16-12. LCD Timer Control Register (LCDTM) Format
Address: FF4AH After Reset: 00H W
Symbol 7 6 5 4 3 2 1 0
LCDTM 0 0 0 0 0 0 TMC21 0
TMC21 LCD Clock Supply Control
0 LCD controller/driver stop mode (supply of LCD clock is stopped)
1 LCD controller/driver operation mode (supply of LCD clock is enabled)
Cautions 1. LCDTM is a special register that must be set when debugging is performed with an in-circuit
emulator. Even if this register is used, the operation of the
µ
PD780852 Subseries is not
affected. However, delete the instruction that manipulates this register from the program at
the final stage of debugging.
2. Bits 7 to 2 and 0 must be set to 0.