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MPC555
/
MPC556
QUEUED SERIAL MULTI-CHANNEL MODULE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
14-19
14.7.1.4 QSPI Control Register 3
SPCR3 contains the loop mode enable bit, halt and mode fault interrupt enable, and
the halt control bit. The CPU has read/write access to SPCR3, but the QSPI has read
access only. SPCR3 must be initialized before QSPI operation begins. Writing a new
value to SPCR3 while the QSPI is enabled disrupts operation.
*See bit descriptions in
SPCR2 —
QSPI Control Register 2
0x30 501C
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
SPIFIE
WREN WRTO
ENDQP
Reserved
NEWQP
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 14-16 SPCR2 Bit Descriptions
Bit(s)
Name
Description
0
SPIFIE
SPI finished interrupt enable. Refer to
0 = QSPI interrupts disabled
1 = QSPI interrupts enabled
1
WREN
14.7.5.7 Master Wraparound Mode
0 = Wraparound mode disabled.
1 = Wraparound mode enabled.
2
WRTO
Wrap to. When wraparound mode is enabled and after the end of queue has been reached,
WRTO determines which address the QSPI executes next. The end of queue is determined by
an address match with ENDQP.
0 = Wrap to pointer address 0x0
1 = Wrap to address in NEWQP
3:7
ENDQP
Ending queue pointer. This field determines the last absolute address in the queue to be com-
pleted by the QSPI. After completing each command, the QSPI compares the queue pointer val-
ue of the just-completed command with the value of ENDQP. If the two values match, the QSPI
sets SPIF to indicate it has reached the end of the programmed queue. Refer to
for more information.
8:10
—
Reserved
11:15
NEWQP
New queue pointer value. This field contains the first QSPI queue address. Refer to
for more information.
SPCR3 —
QSPI Control Register
0x30 501E
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
Reserved
LOOP
Q
HMIE
HALT
SPSR*
RESET:
0
0
0
0
0
0
0
0
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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