
MOTOROLA
REGISTER SUMMARY
MC68336/376
D-64
USER’S MANUAL
The FLAG bit is set by hardware and cleared by software, or by system reset. Clear
the FLAG bit either by writing a zero to it, having first read the bit as a one, or by se-
lecting the DIS mode.
IL[2:0] — Interrupt Level
When the DASM generates an interrupt request, IL[2:0] determines which of the
interrupt request signals is asserted. When a request is acknowledged, the CTM4
compares IL[2:0] to a mask value supplied by the CPU32 to determine whether to
respond. IL[2:0] must have a value in the range of $0 (interrupts disabled) to $7
(highest priority).
IARB3 — Interrupt Arbitration Bit 3
This bit and the IARB[2:0] field in BIUMCR are concatenated to determine the interrupt
arbitration number for the submodule requesting interrupt service. Refer to D.7.1 BIU WOR — Wired-OR Mode
In the DIS, IPWM, IPM and IC modes, the WOR bit is not used. Reading this bit returns
the value that was previously written.
In the OCB, OCAB and OPWM modes, the WOR bit selects whether the output buffer
is configured for open-drain or normal operation.
0 = Output buffer operates in normal mode.
1 = Output buffer operates in open-drain mode.
BSL — Bus Select
This bit selects the time base bus connected to the DASM.
0 = DASM is connected to time base bus A.
1 = DASM is connected to time base bus B.
IN — Input Pin Status
In the DIS, IPWM, IPM and IC modes, this read-only status bit reflects the logic level
on the input pin.
In the OCB, OCAB and OPWM modes, reading this bit returns the value latched on
the output flip-flop, after EDPOL polarity selection.
Writing to this bit has no effect.
Table D-44 DASM Mode Flag Status Bit States
Mode
Flag Status Bit State
DIS
FLAG bit is reset
IPWM
FLAG bit is set each time there is a capture on channel A
IPM
FLAG bit is set each time there is a capture on channel A, except for the first time
IC
FLAG bit is set each time there is a capture on channel A
OCB
FLAG bit is set each time there is a successful comparison on channel B
OCAB
FLAG bit is set each time there is a successful comparison on either channel A or B
OPWM
FLAG bit is set each time there is a successful comparison on channel A
336376UMBook Page 64 Friday, November 15, 1996 2:09 PM