w65c22 Western Design Center, Inc., w65c22 Datasheet - Page 21

• Manufacturer Part Number: w65c22
• Description: W65c22n And W65c22s Versatile Interface Adapter Via Datasheet
• Manufacturer: Western Design Center, Inc.

Notes: 1.
2.12 Shift Register Input Modes
SR7
2.
2.12.1 Shift Register Disabled (000)
In the 000 mode, the SR is disabled from all operation. The microprocessor can read or write the
SR, but shifting is disabled and both CB1 and CB2 are controlled by bits in the PCR. The Shift
Register Interrupt Flag (IFR2) is held low (disabled).
7
When shifting out, bit 7 is the first bit out and simultaneously is rotated back into bit 0.
When shifting in, bits initially enter bit 0 and are shifted towards bit 7.
Table 2-10 Shift Register and Auxiliary Control Register Control ($0A)
SR6
4
0
0
0
0
1
1
1
1
6
3
0
0
1
1
0
0
1
1
SR5
5
2
0
1
0
1
0
1
0
1
7
Operation
Disabled
Shift in under control of T2
Shift in under control of PHI2
Shift in under control of external clock (CB1)
Shift out free running at T2 rate
Shift out under control of T2
Shift out under control of PHI2
Shift out under control of external clock (CB1)
SR4
6
4
Shift Register Control
5
SR3
Shift Register
Mode Control
4
3
3
SR2
2
2
1
SR1
0
1
ACR
SR0
0
SR
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