Intel C2518 FH8065501516710 Data Sheet

Intel

®

 Atom™ Processor C2000 Product Family for Microserver

September 2014

Datasheet, Vol. 2 of 3

Order Number: 330061-002US

279

An Out transaction sends data to the debug device and occurs only when the following 

are true:

• The debug port is enabled.
• The debug software sets the GO_CNT bit.
• The WRITE_READ#_CNT bit is set.

The sequence of the transaction is:

1. The software sets the appropriate values in the following bits:

USB_ADDRESS_CNF
USB_ENDPOINT_CNF
DATA_BUFFER[63:0]
TOKEN_PID_CNT[7:0]
SEND_PID_CNT[15:8]
DATA_LEN_CNT
WRITE_READ#_CNT (Note: This is always 1 for OUT transactions.)
GO_CNT (Note: This is always 1 to initiate the transaction.)

2. The debug port controller sends a token packet consisting of the following:

SYNC
TOKEN_PID_CNT field
USB_ADDRESS_CNT field
USB_ENDPOINT_CNT field
5-bit CRC field

3. After sending the token packet, the debug port controller sends a data packet 

consisting of the following:

SYNC
SEND_PID_CNT field
The number of data bytes indicated in DATA_LEN_CNT from the DATA_BUFFER
16-bit CRC

A DATA_LEN_CNT value of 0 is valid in which case no data bytes are included in the 

packet.

4. After sending the data packet, the controller waits for a handshake response from 

the debug device.

• If a handshake is received, the debug port controller:

a. Places the received PID in the RECEIVED_PID_STS field.
b. Resets the ERROR_GOOD#_STS bit.
c. Sets the DONE_STS bit.

• If no handshake PID is received, the debug port controller:

a. Sets the EXCEPTION_STS field to 001b.
b. Sets the ERROR_GOOD#_STS bit.
c. Sets the DONE_STS bit.