NXP Semiconductors MPC5644A, Reference Manual, Page: 941 / 1735

Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 941
Other operations not related to ALU/MDU in the same microinstruction are not affected by the AS/CE
field.
If a conditional operation is selected, there is no A-Source size override; similarly, when size override for
A-Source is selected, the ALU/MDU operation executes unconditionally.
When a conditional ALU/MDU operation is not executed:
• The destination register is not updated. If the destination is CHAN, no actions associated with
CHAN assignment occur (see
Section , Channel Selection Register – CHAN ).
• The ALU and MDU flags are not updated.
• MDU does not start any operation, i.e., MACH and MACL are not updated.
• SR does not shift.
• T4ABS-selected read-match does not occur.
24.5.9.2.8 A-Source size override
Some values if the AS/CE field are used for A-Source Size Override, as shown in Table 24-91 .
Table 24-90. ALU/MDU conditional execution
AS/CE Meaning
000 Used for A-Source size override (see Section 24.5.9.2.8, A-Source size override )
001
010 execute if C = 1
011 execute if C = 0
100 execute if Z = 1
101 execute if Z = 0
110 execute if N = 1
111 execute unconditionally/no size override
Table 24-91. A-Source size override
AS/CE Meaning
000 A-source size override to 8 bits
001 A-source size override to 16 bits
010 Used for conditional execution (see Section 24.5.9.2.7, Conditional ALU/MDU operation execution )
011
100
101
110
111 execute unconditionally/no size override