BMSKTOPASA900(DCE) Toshiba, BMSKTOPASA900(DCE) Datasheet - Page 625

• Manufacturer Part Number: BMSKTOPASA900(DCE)
• Description: KIT STARTER TMPA900 USB JTAG
• Manufacturer: Toshiba
• Series: TOPASr
• Type: MCUr

Specifications of BMSKTOPASA900(DCE)

• Contents: Evaluation Board, Cable(s), Software and Documentation
• For Use With/related Products: TMPA900CMXBG
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.16.4.2 Appendix B About Setting an Odd Number of Bytes as MaxPacketSize
1. Setting an odd number in the EPx_MaxPacketSize register
Common bus access (PVCI-I/F)
Endpoint direct access (Endpoint-I/F)
The USB specification allows MaxPacketSize (hereafter referred to as MPS) of each endpoint
to be set as either an odd or even number of bytes for Isochronous and Interrupt transfers. (For
Control and Bulk transfers, only an even number can be set.)
In UDC2, MPS is set through max_pkt (bits[10:0]) of the EPx_MaxPacketSize register. The
endpoint FIFOs of UDC2 only support even numbers of bytes. It is therefore recommended
that MSP be set as an even number of bytes as a general rule.
When using MPS by odd bytes, it is possible to make “max_pkt“ into odd number. However,
there are restrictions shown in Table 3.16.3 by the access method of a bus. In the case of
endpoint direct access, an odd number cannot be set in max_pkt for a transmit endpoint. In
this case, an even number should be set in max_pkt and write accesses to the endpoint FIFO
should be controlled to implement an odd number of maximum write bytes. (For example,
when MPS = 1023 bytes, max_pkt should be set to 1024 bytes.)
Based on the above, the following pages describe how to set an odd number of bytes as MPS for
each bus access method.
Table 3.16.3 Restrictions on the setting of max_pkt
An odd or even number can be set.
An odd or even number can be set.
TENTATIVE
TMPA900CM- 624
Receive endpoint
An odd or even number can be set.
Only an even number can be set.
Transmit endpoint
TMPA900CM
2009-10-14