EP7209 Datasheet, PDF (58/128 Pages) Cirrus Logic – Ultra-Low-Power Audio Decoder System-on-Chip

EP7209
Bit
18
19
20
Description
EXCKEN: External expansion clock enable. If this bit is set, the EXPCLK is enabled continu-
ously; it is the same speed and phase as the CPU clock and will free run all the time the main
oscillator is running if this bit is set. This bit should not be left set all the time for power consump-
tion reasons. If the system enters the Standby State, the EXPCLK will become undefined. If this
bit is clear, EXPCLK will be active during memory cycles to expansion slots that have external
wait state generation enabled only.
WAKEDIS: Setting this bit disables waking up from the Standby State, via the wakeup input.
IRTXM: IrDA TX mode bit. This bit controls the IrDA encoding strategy. Clearing this bit means
each zero bit transmitted is represented as a pulse of width 3/16th of the bit rate period. Setting
this bit means each zero bit is represented as a pulse of width 3/16th of the period of 115,200-bit
rate clock (i.e., 1.6 µsec regardless of the selected bit rate). Setting this bit will use less power,
but will probably reduce transmission distances.
Table 27. SYSCON1 (cont.)
58
DS453PP2