Bosch TTCAN - Manual (Page 39)

User’s Manual
BOSCH - 39/77 -
Revision 1.6 TTCAN
11.11.02
manual_about.fm
3.5.22 TT Time Mark Register (addresses 0x6D & 0x6C)
TMark Time Mark
0x0000-0xFFFF An interrupt is generated when the time base indicated by TMC
(Cycle Time, Local Time, or Global Time) has the same value as
Time Mark.
Note : The Time Mark register can only be written while the time mark interrupt is disabled by TMC = 0.
3.5.23 TT Gap Control Register (addresses 0x6F & 0x6E)
EPE Event Pin Enable
one
The EVENT_TRIGGER pin controls the Gaps.
zero The application program controls the Gaps.
TMG Time Mark Gap
one
The next Reference Message is started when the Time Mark
Interrupt TMI becomes active.
zero The bit is reset automatically at each Reference Message.
FGp Finish Gap
one
The next Reference Message is started immediately when
Gap = ‘1’ or else at the next Tx_Ref_Trigger. This bit is set in
TTMODE_3 by the CPU, by a Time Mark Interrupt if TMG = ‘1’,
or by EVENT_TRIGGER pin = ‘0’ if EPE = ‘1’.
zero The bit is reset automatically at each Reference Message.
Gap Now is Gap
one
The Gap time after the Basic Cycle has started and TTMODE_3.
zero No Gap in Schedule, this bit is reset automatically at each Refer-
ence Message and in nodes that are time slaves.
GpH Gap Herald
one
Next_is_Gap = ‘1’ in Reference Message and TTMODE_3.
zero No Gap announced, this bit is reset automatically at each Refer-
ence Message with Next_is_Gap = ‘0’.
NiG Next is Gap
one
Next_is_Gap = ‘1’ will be transmitted in next Reference Mes-
sage(s). This bit can only be set by the CPU in a node that is the
actual time master operating in TTMODE_3.
zero No action. The bit is reset automatically when any Reference
Message transmitted by another node is received.
The time master writes NiG to ‘1’ to initiate a Gap. The Next_is_Gap bit will be transmitted as
‘1’ in the next Reference Message. As soon as that Reference Message is completed, the
GpH bit will announce the Gap to the time master as well as to the time slaves. The current
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
TMark
rw rw
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
res EPE res TMG FGp res Gap GpH NiG
r rw r rw rw r r r rw