NXP Semiconductors K22F series - BDT Page Register 1 (Usbx_Bdtpage1); Frame Number Register Low (Usbx_Frmnuml)

43.4.16 BDT Page register 1 (USBx_BDTPAGE1)
Provides address bits 15 through 9 of the base address where the current Buffer
Descriptor Table (BDT) resides in system memory. See Buffer Descriptor Table. The 32-
bit BDT Base Address is always aligned on 512-byte boundaries, so bits 8 through 0 of
the base address are always zero.
Address:
4007_2000h base + 9Ch offset = 4007_209Ch
Bit 7 6 5 4 3 2 1 0
Read
BDTBA
0
Write
Reset
0 0 0 0 0 0 0 0
USBx_BDTPAGE1 field descriptions
Field Description
7–1
BDTBA
Provides address bits 15 through 9 of the BDT base address.
0
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
43.4.17 Frame Number register Low (USBx_FRMNUML)
The Frame Number registers (low and high) contain the 11-bit frame number. These
registers are updated with the current frame number whenever a SOF TOKEN is
received.
Address:
4007_2000h base + A0h offset = 4007_20A0h
Bit 7 6 5 4 3 2 1 0
Read
FRM[7:0]
Write
Reset
0 0 0 0 0 0 0 0
USBx_FRMNUML field descriptions
Field Description
FRM[7:0] This 8-bit field and the 3-bit field in the Frame Number Register High are used to compute the address
where the current Buffer Descriptor Table (BDT) resides in system memory.
Memory map/Register definitions
K22F Sub-Family Reference Manual, Rev. 4, 08/2016
1098 NXP Semiconductors