REGISTER SUMMARY
M68HC16 Z SERIES
D-40
USER’S MANUAL
ILQSPI[2:0] — Interrupt Level for QSPI
When an interrupt request is made, the ILQSPI value determines the priority level of
all QSPI interrupts. When a request is acknowledged, the QSM compares this value
to a mask value supplied by the CPU16 to determine whether to respond. ILQSPI must
have a value in the range $0 (interrupts disabled) to $7 (highest priority).
ILSCI[2:0] — Interrupt Level for SCI
When an interrupt request is made, the ILSCI value determines the priority level of all
SCI interrupts. When a request is acknowledged, the QSM compares this value to a
mask value supplied by the CPU16 to determine whether to respond. The field must
have a value in the range $0 (interrupts disabled) to $7 (highest priority).
If ILQSPI[2:0] and ILSCI[2:0] have the same non-zero value, and both submodules si-
multaneously request interrupt service, the QSPI takes priority over the SCI.
INTV[7:0] — Interrupt Vector Number
The value of INTV[7:1] is used for both QSPI and SCI interrupt requests; the value of
INTV0 used during an interrupt acknowledge cycle is supplied by the QSM. INTV0 is
at logic level zero during an SCI interrupt and at logic level one during a QSPI interrupt.
A write to INTV0 has no effect. Reads of INTV0 return a value of one. At reset, QIVR
is initialized to $0F, the uninitialized interrupt vector number. To use interrupt-driven
serial communication, a user-defined vector number must be written to QIVR.
D.6.4 SCI Control Register
SCCR0 contains the SCI baud rate selection field. Baud rate must be set before the
SCI is enabled. The CPU16 can read and write SCCR0 at any time. Changing the val-
ue of SCCR0 bits during a transfer operation disrupts operation.
Bits [15:13] — Not Implemented
SCBR[12:0] — SCI Baud Rate
SCI baud rate is programmed by writing a 13-bit value to this field. Writing a value of
zero to SCBR disables the baud rate generator. The baud clock rate is calculated as
follows:
or
where SCBR[12:0] is in the range of 1 to 8191.
SCCR0 — SCI Control Register 0
$YFFC08
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NOT USED
SCBR[12:0]
RESET:
0
0
0
0
0
0
0
0
0
0
1
0
0
SCI Baud Rate
f
sys
32
SCBR[12:0]
×
--------------------------------------------
=
SCBR[12:0]
f
sys
32
SCI Baud Rate Desired
×
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=
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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