
C8051F340/1/2/3/4/5/6/7
SFR Definition 16.1. USB0XCN: USB0 Transceiver Control
R/W | R/W | R/W | R/W | R/W | R | R | R | Reset Value |
PREN | PHYEN | SPEED | PHYTST1 | PHYTST0 | DFREC | Dp | Dn |
Bit7 | Bit6 | Bit5 | Bit4 | Bit3 | Bit2 | Bit1 | Bit0 |
00000000
SFR Address:
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| 0xD7 |
Bit7: | PREN: Internal |
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| The location of the | |||||
| 0: Internal | |||||
| 1: Internal | |||||
| work). |
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Bit6: | PHYEN: Physical Layer Enable |
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| This bit enables/disables the USB0 physical layer transceiver. | |||||
| 0: Transceiver disabled (suspend). |
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| 1: Transceiver enabled (normal). |
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Bit5: | SPEED: USB0 Speed Select |
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| This bit selects the USB0 speed. |
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| 0: USB0 operates as a Low Speed device. If enabled, the internal | |||||
| on the D– line. |
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| 1: USB0 operates as a Full Speed device. If enabled, the internal | |||||
| the D+ line. |
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| These bits can be used to test the USB0 transceiver. |
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| PHYTST[1:0] | Mode |
| D+ | D– |
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| 00b | Mode 0: Normal |
| X | X |
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| 01b | Mode 1: Differential ‘1’ Forced |
| 1 | 0 |
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| 10b | Mode 2: Differential ‘0’ Forced |
| 0 | 1 |
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| 11b | Mode 3: |
| 0 | 0 |
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Bit2: | DFREC: Differential Receiver |
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| The state of this bit indicates the current differential value present on the D+ and D– lines | |||||
| when PHYEN = ‘1’. |
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| 0: Differential ‘0’ signaling on the bus. |
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| 1: Differential ‘1’ signaling on the bus. |
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Bit1: | Dp: D+ Signal Status |
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| This bit indicates the current logic level of the D+ pin. |
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| 0: D+ signal currently at logic 0. |
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| 1: D+ signal currently at logic 1. |
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Bit0: | Dn: D- Signal Status |
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| This bit indicates the current logic level of the D– pin. |
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0: D– signal currently at logic 0.
1: D– signal currently at logic 1.
Rev. 0.5 | 165 |