Datasheet

32.8.2.1 Control B
Name: CTRLB
Offset: 0x08
Reset: 0x0000
Property: PAC Write-Protection
Bit 15 14 13 12 11 10 9 8
LPMHDSK[1:0] GNAK
Access
R/W R/W R/W
Reset 0 0 0
Bit 7 6 5 4 3 2 1 0
NREPLY SPDCONF[1:0] UPRSM DETACH
Access
R R/W R/W R/W R/W
Reset 0 0 0 0 0
Bits 11:10 – LPMHDSK[1:0] Link Power Management Handshake
These bits select the Link Power Management Handshake configuration.
Value Description
0x0
No handshake. LPM is not supported.
0x1
ACK
0x2
NYET
0x3
Reserved
Bit 9 – GNAK Global NAK
This bit configures the operating mode of the NAK.
This bit is not synchronized.
Value Description
0
The handshake packet reports the status of the USB transaction
1
A NAK handshake is answered for each USB transaction regardless of the current endpoint
memory bank status
Bit 4 – NREPLY No reply excepted SETUP Token
This bit is cleared by hardware when receiving a SETUP packet.
This bit has no effect for any other endpoint but endpoint 0.
Value Description
0
Disable the “NO_REPLY” feature: Any transaction to endpoint 0 will be handled according to
the USB2.0 standard.
1
Enable the “NO_REPLY” feature: Any transaction to endpoint 0 will be ignored except
SETUP.
Bits 3:2 – SPDCONF[1:0] Speed Configuration
These bits select the speed configuration.
SAM D21 Family
USB – Universal Serial Bus
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 826