9397 750 XXXXX
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 01 — 15 August 2005
208
Philips Semiconductors
UM10139
Volume 1
Chapter 14: USB Device Controller
14.7.12 USB
Realize
Endpoint register (USBReEp - 0xE009 0044)
Though fixed-endpoint configuration implements 32 endpoints, it is not a must that all
have to be used. If the endpoint has to be used, it should have buffer space in the
EP_RAM. The EP_RAM space can be optimized by realizing a subset of endpoints. This
is done through programming the Realize Endpoint register. Each physical endpoint has
one bit as shown in
. The USBReEp is a read/write register.
At power on only default control endpoint is realized. Other endpoints if required have to
be realized by programming the corresponding bit in the Realize Endpoint register.
Realization of endpoints is a multi-cycle operation. The pseudo code of endpoint
realization is shown below.
for every endpoint to be realized,
Bit
23
22
21
20
19
18
17
16
Symbol
EP11TX
EP11RX
EP10TX
EP10RX
EP9TX
EP9RX
EP8TX
EP8RX
Bit
15
14
13
12
11
10
9
8
Symbol
EP7TX
EP7RX
EP6TX
EP6RX
EP5TX
EP5RX
EP4TX
EP4RX
Bit
7
6
5
4
3
2
1
0
Symbol
EP3TX
EP3RX
EP2TX
EP2RX
EP1TX
EP1RX
EP0TX
EP0RX
Table 194: USB Endpoint Interrupt Priority register (USBEpIntPri - address 0xE009 0040) bit description
Bit
Symbol
Value
Description
Reset value
31:0
See
USBEpIntPri
bit allocation
table above
0
The corresponding interrupt will be routed to the slow endpoint interrupt bit
in the Device Status register.
0
1
The corresponding interrupt will be routed to the fast endpoint interrupt bit
in the Device Status register.
Table 195: USB Realize Endpoint register (USBReEp - address 0xE009 0044) bit allocation
Reset value: 0x0000 0003
Bit
31
30
29
28
27
26
25
24
Symbol
EP31
EP30
EP29
EP28
EP27
EP26
EP25
EP24
Bit
23
22
21
20
19
18
17
16
Symbol
EP23
EP22
EP21
EP20
EP19
EP18
EP17
EP16
Bit
15
14
13
12
11
10
9
8
Symbol
EP15
EP14
EP13
EP12
EP11
EP10
EP9
EP8
Bit
7
6
5
4
3
2
1
0
Symbol
EP7
EP6
EP5
EP4
EP3
EP2
EP1
EP0
Table 196: USB Realize Endpoint register (USBReEp - address 0xE009 0044) bit description
Bit
Symbol
Value
Description
Reset value
0
EP0
0
Control endpoint EP0 is not realized.
1
1
Control endpoint EP0 is realized.
1
EP1
0
Control endpoint EP1 is not realized.
1
1
Control endpoint EP1 is realized.
31:2
EPxx
0
Endpoint EPxx is not realized.
0
1
Endpoint EPxx is realized.