MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
665
Preliminary—Subject to Change Without Notice
Figure 22-32. Input Period Measurement example
describes the A1 and B1 register updates when EMIOSA[n] and EMIOSB[n] read operations
are performed. When EMIOSA[n] read occurs the content of A1 is transferred to B1 thus providing
coherent data in A2 and B1 registers. Transfers from B2 to B1 are then blocked until EMIOSB[n] is read.
After EMIOSB[n] is read, register A1 content is transferred to register B1 and the transfers from B2 to B1
are re-enabled to occur at the transfer edges, which is the leading edge in the
Figure 22-33. A1 and B1 updates at EMIOSA[n] and EMIOSB[n] reads
22.5.1.1.6
Double Action Output Compare (DAOC) Mode
In the DAOC mode the leading and trailing edges of the variable pulse width output are generated by
matches occurring on comparators A and B. There is no restriction concerning the order in which A and
B matches occur.
When the DAOC mode is entered, coming out from GPIO mode both comparators are disabled and the
output flip-flop is set to the complement of the EDPOL bit in the EMIOSC[n] register.
selected counter bus
$000500
$001000
$001100
$001250
$001525
$0016A0
A2(captured) value
2
A1 value
B2 (captured) value
$xxxxxx
$001000
$001250
$xxxxxx
$001000
$001250
$0016A0
$xxxxxx
$001000
$001250
$0016A0
Input signal
1
EDPOL = 1
FLAG pin register
Notes: 1. After input filter
2. EMIOSA[n] = A2
3. EMIOSB[n] = B1
A
A
A
B1 value
3
$xxxxxx
$001000
$001250
selected counter bus
$000500
$001000
$001100
$001250
$001525
$0016A0
A2(captured) value
2
B2(captured) value
B1 value
3
$xxxxxx
$001000
$001250
$0016A0
$xxxxxx
$001000
$xxxxxx
$001000
Input signal
1
A
A
A
FLAG pin/register
EDPOL = 1
A1 value
$xxxxxx
$001000
$001000
$001250
$001250
Read EMIOSA[n]
Read EMIOSB[n]
$001250
Notes: 1. After input filter
2. EMIOSA[n] = A2
3. EMIOSB[n] = B1
$0016A0