Clean up USB spec references.

exercise-book/src/nrf52-usb-device-descriptor.md

@@ -4,9 +4,9 @@
 
 After receiving a `GET_DESCRIPTOR` request during the __SETUP__ stage, the device needs to respond with the actual *descriptor* data during the __DATA__ stage. In our Rust application, this descriptor will be generated using some library code and serialised into an array of bytes which we can give to the USBD peripheral.
 
-A descriptor is a binary encoded data structure sent by the device to the host. The device descriptor, in particular, contains information about the device, like its product and vendor identifiers and how many *configurations* it has. The format of the device descriptor is specified in section 9.6.1, Device, of the [USB specification][usb_spec].
+A descriptor is a binary encoded data structure sent by the device to the host. The device descriptor, in particular, contains information about the device, like its product and vendor identifiers and how many *configurations* it has. The format of the device descriptor is specified in Section 9.6.1 of the [USB specification].
 
-[usb_spec]: ./nrf52-usb-usb-specification.md
+[USB specification]: ./nrf52-usb-usb-specification.md
 
 As far as the enumeration process goes, the most relevant fields of the device descriptor are the number of configurations and `bcdUSB`, the version of the USB specification the devices adheres to. In `bcdUSB` you should report compatibility with USB 2.0.
 

exercise-book/src/nrf52-usb-getting-device-configured.md

@@ -18,14 +18,14 @@ Now modify the `usb-descriptors` command within the `xtask` package to "open" th
 
 ## SET_CONFIGURATION
 
-The SET_CONFIGURATION request is sent by the host to configure the device. Its configuration according to section 9.4.7. of the [USB specification][usb_spec] is:
+The SET_CONFIGURATION request is sent by the host to configure the device. Its configuration according to Section 9.4.7 of the [USB specification] is:
 
 - `bmrequesttype` is **0b00000000**
 - `brequest` is **9** (i.e. the SET_CONFIGURATION Request Code, see table 9-4 in the USB spec)
 - `wValue` contains the requested configuration value
 - `wIndex` and `wLength` are 0, there is no `wData`
 
-[usb_spec]: ./nrf52-usb-usb-specification.md
+[USB specification]: ./nrf52-usb-usb-specification.md
 
 ✅ To handle a SET_CONFIGURATION, do the following:
 

exercise-book/src/nrf52-usb-setup-stage.md

@@ -67,7 +67,7 @@ In this step of the exercise, we only need to parse DEVICE descriptor requests.
 - the wIndex is **0** for our purposes
 - ❗️you need to fetch the descriptor type from the high byte of `wValue`, and the descriptor index from the the low byte of `wValue`
 
-Check section 9.4.3 of the [USB specification][usb_spec] for a very detailed description of the requests. All the constants we'll be using are also described in Tables 9-3, 9-4 and 9-5 of the same document. Or, you can refer to [Chapter 6 of USB In a Nutshell](https://www.beyondlogic.org/usbnutshell/usb6.shtml).
+Check Section 9.4.3 of the [USB specification] for a very detailed description of the requests. All the constants we'll be using are also described in Tables 9-3, 9-4 and 9-5 of the same document. Or, you can refer to [Chapter 6 of USB In a Nutshell](https://www.beyondlogic.org/usbnutshell/usb6.shtml).
 
 You should return `Err(Error::xxx)` if the properties aren't met.
 
@@ -77,7 +77,6 @@ You should return `Err(Error::xxx)` if the properties aren't met.
 - use bit shifts (`>>`) and casts (`as u8`) to get the high/low bytes of `wValue`
 
 You will also find this information in the `// TODO implement ...` comment in the `Request::parse()` function of `lib.rs` file.
- > NOTE: If you'd like to learn more, take a look at Section 9.4.3 Get Descriptor of the USB specification.
 
 See [`nrf52-code/usb-lib-solutions/get-device/src/lib.rs`](../../nrf52-code/usb-lib-solutions/get-device/src/lib.rs) for a solution.
 
@@ -115,5 +114,5 @@ Goal reached; move to the next section
 
 You can find a solution to this step in [`nrf52-code/usb-app-solutions/src/bin/usb-2.rs`](../../nrf52-code/usb-app-solutions/src/bin/usb-2.rs).
 
-[usb_spec]: ./nrf52-usb-usb-specification.md
+[USB specification]: ./nrf52-usb-usb-specification.md
 [usb_2]: ../../nrf52-code/usb-app/src/bin/usb-2.rs

exercise-book/src/nrf52-usb-supporting-standard-requests.md

@@ -15,13 +15,13 @@ When the host issues a GET_DESCRIPTOR *Configuration* request the device needs t
 As a reminder, all GET_DESCRIPTOR request types share the following properties:
 
 - `bmRequestType` is **0b10000000**
-- `bRequest` is **6** (i.e. the GET_DESCRIPTOR Request Code, defined in table 9-4 of the [USB specification][usb_spec])
+- `bRequest` is **6** (i.e. the GET_DESCRIPTOR Request Code, defined in Table 9-4 of the [USB specification])
 
 A GET_DESCRIPTOR *Configuration* request is determined by the high byte of its `wValue` field:
 
-- The high byte of `wValue` is **2** (i.e. the `CONFIGURATION` descriptor type, defined in table 9-5 of the [USB specification][usb_spec])
+- The high byte of `wValue` is **2** (i.e. the `CONFIGURATION` descriptor type, defined in Table 9-5 of the [USB specification])
 
-[usb_spec]: ./nrf52-usb-usb-specification.md
+[USB specification]: ./nrf52-usb-usb-specification.md
 
 ✅ Update the parser in [`nrf52-code/usb-lib`](../../nrf52-code/usb-lib) to handle `SET_CONFIGURATION` requests.
 

exercise-book/src/nrf52-usb-usb-endpoints.md

@@ -16,4 +16,4 @@ Going back to our [enumeration steps](./nrf52-usb-usb-enumeration.md), we are ex
 
 For detailed information about endpoints check Section 5.3.1 *Device Endpoints*, in the [USB 2.0 specification][usb_spec]. Or you can look at [Chapter 3 of USB In a Nutshell](https://www.beyondlogic.org/usbnutshell/usb3.shtml#Endpoints).
 
-[usb_spec]: ./nrf52-usb-usb-specification.md
+[USB specification]: ./nrf52-usb-usb-specification.md