Chapter 13 Programmable Trigger Unit (PTUV3)MC9S12ZVMB Family Reference Manual Rev. 1.3NXP Semiconductors 47313.3.2.14 PTU Debug Register (PTUDEBUG )13.4 Functional Description13.4.1 GeneralThe PTU module consists of one trigger generator (TG0).If the trigger generator is disabled then the PTU is disabled, the trigger generation stops and the memoryaccesses are disabled.The trigger generation of the PTU module is synchronized to the incoming reload event. This reload eventresets and restarts the internal time base counter and makes sure that the first trigger value from the actualtrigger list is loaded. Furthermore the corresponding module is informed that a new control cycle hasstarted.If the counter value matches the current trigger value then a trigger event is generated. In this way, thereload event is delayed by the number of bus clock cycles defined by the current trigger value. After this,a new trigger value is loaded from the memory and the TG0 wait for the next match. So up to 32 triggerevents per control cycle can be generated. If the trigger value is 0x0000 or 32 trigger events have beenModule Base + 0x001F Access: User read/write (1)1. Read: AnytimeWrite: only in special mode7 6 5 4 3 2 1 0R 0PTUREPE0PTUT0PE0 0 0 0W PTUFRE TG0FTEReset 0 0 0 0 0 0 0 0= UnimplementedFigure 13-16. PTU Debug Register (PTUDEBUG)Table 13-16. PTUDEBUG Register Field DescriptionsField Description6PTUREPEPTURE Pin Enable — This bit enables the output port for pin PTURE.0 PTURE output port are disabled1 PTURE output port are enabled4PTUT0PEPTU PTUT0 Pin Enable — This bit enables the output port for pin PTUT0.0 PTUT0 output port are disabled1 PTUT0 output port are enabled2PTUFREForce Reload event generation — If one of the TGs is enabled then writing 1 to this bit will generate a reloadevent. The reload event forced by PTUFRE does not set the PTUROIF interrupt flag. Also the ptu_reload signalasserts for one bus clock cyclet. Writing 0 to this bit has no effect. Always reads back as 0. This behavior is notavailable during stop or freeze mode.0TG0FTETrigger Generator 0 Force Trigger Event — If TG0 is enabled then writing 1 to this bit will generate a triggerevent independent on the list based trigger generation. Writing 0 to this bit has no effect. Always reads back as0. This behavior is not available during stop or freeze mode.
