Jameco Electronics Rabbit 3000 - Manual (Page 186)

User’s Manual 177
Table 12-18. Extended Register Clocked Serial Mode (Ports A-D only)
Serial Port x Extended Register (SAER) (Address = 0xC5)
(SBER) (Address = 0xD5)
(SCER) (Address = 0xE5)
(SDER) (Address = 0xF5)
Bit(s) Value Description (Clocked serial mode only)
7
0 Normal clocked serial operation.
1 Timer synchronized clocked serial operation.
6
0 Timer-synchronized clocked serial uses Timer B1.
1 Timer-synchronized clocked serial uses Timer B2.
5:4
00 Normal clocked serial clock polarity, inactive High. Internal or external clock.
01 Normal clocked serial clock polarity, inactive Low. Internal clock only.
10 Inverted clocked serial clock polarity, inactive Low. Internal or external clock.
11 Inverted clocked serial clock polarity, inactive High. Internal clock only.
3:2 xx These bits are ignored in clocked serial mode.
1
0 No effect on transmitter.
1 Terminate current clocked serial transmission. No effect on buffer.
0
0 No effect on receiver.
1 Terminate current clocked serial reception.