I encount similar problems, that's because this code is for old TWR-K60DN512 board, while you are use TWR-K60D100 board, the chip on these two board have different mask, though they have same name, the new board's K60 with mask 4N22D add one CHN bit in PIT_TCTRL1 register, in the orginal code, it is below red code, it write PIT_TCTRL1=0xffff fffD, , after change it to bluw code, the PIT can runs well, also the code can runs well. I write a post in link: Kinetis USB Host MSD bootloader 应用笔记AN4368的一个小Bug - FSL_FAE_ConstYu的博客 - 与非博客 - 与非网
PIT_TCTRL1 = ~PIT_TCTRL_TEN_MASK;
PIT_TCTRL1 = ~PIT_TCTRL_TIE_MASK; //初始代码
// PIT_TCTRL1 = 0x01； //修改后代码
of course, there are also have other several problems like below, I am finding the solution.
1. it only support S19 with S3 formate, while the IAR generated S2 formate S19 file.
2. it can't support bin formate.
