DocID018909 Rev 11
RM0090
USB on-the-go high-speed (OTG_HS)
1529
Once the MAC receives an IN token, this information (token received) is synchronized to the
AHB clock by the PFC (the PFC runs on the AHB clock). The PFC then reads the data from
the SPRAM and writes them into the dual clock source buffer. The MAC then reads the data
out of the source buffer (4 deep).
If the AHB is running at a higher frequency than the PHY, the application can use a smaller
value for TRDT (in OTG_HS_GUSBCFG).
has the following signals:
•
tkn_rcvd: Token received information from MAC to PFC
•
dynced_tkn_rcvd: Doubled sync tkn_rcvd, from PCLK to HCLK domain
•
spr_read: Read to SPRAM
•
spr_addr: Address to SPRAM
•
spr_rdata: Read data from SPRAM
•
srcbuf_push: Push to the source buffer
•
srcbuf_rdata: Read data from the source buffer. Data seen by MAC
for the values of TRDT versus AHB clock frequency.
Figure 427. TRDT max timing case
1
2
3
4
5
6
7
8
0ns
50ns
100ns
150ns
200ns
HCLK
PCLK
tkn_rcvd
dsynced_tkn_rcvd
spr_read
spr_addr
spr_rdata
src
b
uf_push
src
b
uf_rdata
5 Clocks
D1
A1
D1
ai15680