diff --git a/src/en/overlay/iface-gpclk.md b/src/en/overlay/iface-gpclk.md
index 2c5e38f..1d796bb 100644
--- a/src/en/overlay/iface-gpclk.md
+++ b/src/en/overlay/iface-gpclk.md
@@ -4,7 +4,7 @@ class: interface
 type: pinout
 name: GPCLK
 description: Raspberry Pi General Purpose Clock
-pincount: 4
+pincount: 3
 pin:
   'bcm4':
     name: GPCLK0
diff --git a/src/en/overlay/iface-jtag.md b/src/en/overlay/iface-jtag.md
new file mode 100644
index 0000000..b4b3ca6
--- /dev/null
+++ b/src/en/overlay/iface-jtag.md
@@ -0,0 +1,34 @@
+<!--
+---
+class: interface
+type: pinout
+name: JTAG
+description: Raspberry Pi JTAG pins
+pincount: 11
+pin:
+  'bcm4':
+    name: TDI (Alt5)
+  'bcm5':
+    name: TDO (Alt5)
+  'bcm6':
+    name: RTCK (Alt5)
+  'bcm12':
+    name: TMS (Alt5)
+  'bcm13':
+    name: TCK (Alt5)
+  'bcm22':
+    name: TRST (Alt4)
+  'bcm23':
+    name: RTCK (Alt4)
+  'bcm24':
+    name: TDO (Alt4)
+  'bcm25':
+    name: TCK (Alt4)
+  'bcm26':
+    name: TDI (Alt4)
+  'bcm27':
+    name: TMS (Alt4)
+-->
+#JTAG - Joint Test Action Group
+
+###JTAG is a standardised interface for debugging integrated circuits which you can use to debug your Raspberry Pi
\ No newline at end of file
diff --git a/src/en/overlay/iface-sd.md b/src/en/overlay/iface-sd.md
index 9fdc6b9..e4ff2b3 100644
--- a/src/en/overlay/iface-sd.md
+++ b/src/en/overlay/iface-sd.md
@@ -4,7 +4,7 @@ class: interface
 type: pinout
 name: SD
 description: Raspberry Pi SD0/SD1 pins
-pincount: 4
+pincount: 6
 pin:
   'bcm22':
     name: CLK
diff --git a/src/en/pi-pinout.yaml b/src/en/pi-pinout.yaml
index 8217988..29189d2 100644
--- a/src/en/pi-pinout.yaml
+++ b/src/en/pi-pinout.yaml
@@ -16,8 +16,9 @@ pins:
       bcm: 2
       bcmAlt: 0
     functions:
-      alt0: SDA1
-      alt1: SA3
+      alt0: I2C1 SDA
+      alt1: SMI SA3
+      alt2: DPI V-Sync
   '4':
     name: 5v Power
     type: "+5v"
@@ -30,8 +31,9 @@ pins:
       bcm: 3
       bcmAlt: 1
     functions:
-      alt0: SCL1
-      alt1: SA2
+      alt0: I2C1 SCL
+      alt1: SMI SA2
+      alt2: DPI H-Sync
   '6':
     name: Ground
     type: GND
@@ -43,8 +45,9 @@ pins:
       bcm: 4
     functions:
       alt0: GPCLK0
-      alt1: SA1
-      alt5: ARM_TDI
+      alt1: SMI SA1
+      alt: Blue 2
+      alt5: JTAG TDI
   '8':
     name: TXD
     description: UART Transmit
@@ -53,10 +56,10 @@ pins:
       wiringpi: 15
       bcm: 14
     functions:
-      alt0: TXD0
-      alt1: SD6
-      alt2: Reserved
-      alt5: TXD1
+      alt0: UART0 TXD
+      alt1: SMI SD6
+      alt2: DSI Green 6
+      alt5: UART1 TXD
   '9':
     name: Ground
     type: GND
@@ -68,10 +71,10 @@ pins:
       wiringpi: 16
       bcm: 15
     functions:
-      alt0: RXD0
-      alt1: SD7
-      alt2: Reserved
-      alt5: RXD1
+      alt0: UART0 RXD
+      alt1: SMI SD7
+      alt2: DPI Green 7
+      alt5: UART1 RXD
   '11':
     name: ''
     type: GPIO
@@ -80,11 +83,11 @@ pins:
       bcm: 17
     functions:
       alt0: Reserved
-      alt1: SD9
-      alt2: Reserved
-      alt3: RTS0
-      alt4: SPI1_CE1_N
-      alt5: RTS1
+      alt1: SMI SD9
+      alt2: DPI Red 3
+      alt3: UART0 RTS
+      alt4: SPI1 CE1
+      alt5: UART1 RTS
   '12':
     name: PWM0
     description: PWM0
@@ -93,11 +96,11 @@ pins:
       wiringpi: 1
       bcm: 18
     functions:
-      alt0: PCM_CLK
-      alt1: SD10
-      alt2: Reserved
+      alt0: PCM CLK
+      alt1: SMI SD10
+      alt2: DPI Red 4
       alt3: BSCSL SDA / MOSI
-      alt4: SPI1_CE0_N
+      alt4: SPI1 CE0
       alt5: PWM0
   '13':
     name: ''
@@ -107,11 +110,11 @@ pins:
       bcm: 27
       bcmAlt: 21
     functions:
-      alt0: Reserved
+      alt0: SD0 DAT3
       alt1: Reserved
       alt2: Reserved
-      alt3: SD1_DAT3
-      alt4: ARM_TMS
+      alt3: SD1 DAT3
+      alt4: JTAG TMS
   '14':
     name: Ground
     type: GND
@@ -122,11 +125,11 @@ pins:
       wiringpi: 3
       bcm: 22
     functions:
-      alt0: Reserved
-      alt1: SD14
+      alt0: SD0 CLK
+      alt1: SMI SD14
       alt2: Reserved
-      alt3: SD1_CLK
-      alt4: ARM_TRST
+      alt3: SD1 CLK
+      alt4: JTAG TRST
   '16':
     name: ''
     type: GPIO
@@ -134,11 +137,11 @@ pins:
       wiringpi: 4
       bcm: 23
     functions:
-      alt0: Reserved
-      alt1: SD15
+      alt0: SD0 CMD
+      alt1: SMI SD15
       alt2: Reserved
-      alt3: SD1_CMD
-      alt4: ARM_RTCK
+      alt3: SD1 CMD
+      alt4: JTAG RTCK
   '17':
     name: 3v3 Power
     type: "+3v3"
@@ -149,11 +152,11 @@ pins:
       wiringpi: 5
       bcm: 24
     functions:
-      alt0: Reserved
-      alt1: SD16
+      alt0: SD0 DAT0
+      alt1: SMI SD16
       alt2: Reserved
-      alt3: SD1_DAT0
-      alt4: ARM_TDO
+      alt3: SD1 DAT0
+      alt4: JTAG TDO
   '19':
     name: MOSI
     type: GPIO/SPI
@@ -161,9 +164,9 @@ pins:
       wiringpi: 12
       bcm: 10
     functions:
-      alt0: SPI0_MOSI
-      alt1: SD2
-      alt2: Reserved
+      alt0: SPI0 MOSI
+      alt1: SMI SD2
+      alt2: DPI Green 2
   '20':
     name: Ground
     type: GND
@@ -174,9 +177,9 @@ pins:
       wiringpi: 13
       bcm: 9
     functions:
-      alt0: SPI0_MISO
-      alt1: SD1
-      alt2: Reserved
+      alt0: SPI0 MISO
+      alt1: SMI SD1
+      alt2: DPI Blue 7
   '22':
     name: ''
     type: GPIO
@@ -184,11 +187,11 @@ pins:
       wiringpi: 6
       bcm: 25
     functions:
-      alt0: Reserved
-      alt1: SD17
+      alt0: SD0 DAT1
+      alt1: SMI SD17
       alt2: Reserved
-      alt3: SD1_DAT1
-      alt4: ARM_TCK
+      alt3: SD1 DAT1
+      alt4: JTAG TCK
   '23':
     name: SCLK
     type: GPIO/SPI
@@ -196,9 +199,9 @@ pins:
       wiringpi: 14
       bcm: 11
     functions:
-      alt0: SPI0_SCLK
-      alt1: SD3
-      alt2: Reserved
+      alt0: SPI0 SCLK
+      alt1: SMI SD3
+      alt2: DPI Green 3
   '24':
     name: CE0
     description: SPI Chip Select 0
@@ -207,9 +210,9 @@ pins:
       wiringpi: 10
       bcm: 8
     functions:
-      alt0: SPI0_CE0_N
-      alt1: SD0
-      alt2: Reserved
+      alt0: SPI0 CE0
+      alt1: SMI SD0
+      alt2: DPI Blue 6
   '25':
     name: Ground
     type: GND
@@ -221,9 +224,9 @@ pins:
       wiringpi: 11
       bcm: 7
     functions:
-      alt0: SPI0_CE1_N
-      alt1: SWE_N / SRW_N
-      alt2: Reserved
+      alt0: SPI0 CE1
+      alt1: SMI SWE_N / SRW_N
+      alt2: DPI Blue 5
   '27':
     name: ID_SD
     description: HAT EEPROM i2c Data
@@ -232,9 +235,9 @@ pins:
       wiringpi: 30
       bcm: 0
     functions:
-      alt0: SDA0
-      alt1: SA5
-      alt2: Reserved
+      alt0: I2C0 SDA
+      alt1: SMI SA5
+      alt2: DPI CLK
   '28':
     name: ID_SC
     description: HAT EEPROM i2c Clock
@@ -243,9 +246,9 @@ pins:
       wiringpi: 31
       bcm: 1
     functions:
-      alt0: SCL0
-      alt1: SA4
-      alt2: Reserved
+      alt0: I2C0 SCL
+      alt1: SMI SA4
+      alt2: DPI DEN
   '29':
     name: ''
     type: GPIO
@@ -254,9 +257,9 @@ pins:
       bcm: 5
     functions:
       alt0: GPCLK1
-      alt1: SA0
-      alt2: Reserved
-      alt5: ARM_TDO
+      alt1: SMI SA0
+      alt2: DPI Blue 3
+      alt5: JTAG TDO
   '30':
     name: Ground
     type: GND
@@ -268,9 +271,9 @@ pins:
       bcm: 6
     functions:
       alt0: GPCLK2
-      alt1: SOE_N / SE
-      alt2: Reserved
-      alt5: ARM_RTCK
+      alt1: SMI SOE_N / SE
+      alt2: DPI Blue 4
+      alt5: JTAG RTCK
   '32':
     name: PWM0
     type: GPIO
@@ -279,9 +282,9 @@ pins:
       bcm: 12
     functions:
       alt0: PWM0
-      alt1: SD4
-      alt2: Reserved
-      alt5: ARM_TMS
+      alt1: SMI SD4
+      alt2: DPI Green 4
+      alt5: JTAG TMS
   '33':
     name: PWM1
     type: GPIO
@@ -290,9 +293,9 @@ pins:
       bcm: 13
     functions:
       alt0: PWM1
-      alt1: SD5
-      alt2: Reserved
-      alt5: ARM_TCK
+      alt1: SMI SD5
+      alt2: DPI Green 5
+      alt5: JTAG TCK
   '34':
     name: Ground
     type: GND
@@ -304,11 +307,11 @@ pins:
       wiringpi: 24
       bcm: 19
     functions:
-      alt0: PCM_FS
-      alt1: SD11
-      alt2: Reserved
+      alt0: PCM FS
+      alt1: SMI SD11
+      alt2: DPI Red 5
       alt3: BSCSL SCL / SCLK
-      alt4: SPI1_MISO
+      alt4: SPI1 MISO
       alt5: PWM1
   '36':
     name: ''
@@ -318,11 +321,11 @@ pins:
       bcm: 16
     functions:
       alt0: Reserved
-      alt1: SD8
-      alt2: Reserved
-      alt3: CTS0
-      alt4: SPI1_CE2_N
-      alt5: CTS1
+      alt1: SMI SD8
+      alt2: DPI Red 2
+      alt3: UART0 CTS
+      alt4: SPI1 CE2
+      alt5: UART1 CTS
   '37':
     name: ''
     type: GPIO
@@ -330,11 +333,11 @@ pins:
       wiringpi: 25
       bcm: 26
     functions:
-      alt0: Reserved
+      alt0: SD0 DAT2
       alt1: Reserved
       alt2: Reserved
-      alt3: SD1_DAT2
-      alt4: ARM_TDI
+      alt3: SD1 DAT2
+      alt4: JTAG TDI
   '38':
     name: MOSI
     description: SPI Master-Out
@@ -343,11 +346,11 @@ pins:
       wiringpi: 28
       bcm: 20
     functions:
-      alt0: PCM_DIN
-      alt1: SD12
-      alt2: Reserved
-      alt3: BSCSL / MISO
-      alt4: SPI1_MOSI
+      alt0: PCM DIN
+      alt1: SMI SD12
+      alt2: DPI Red 6
+      alt3: BSCSL MISO
+      alt4: SPI1 MOSI
       alt5: CPCLK0
   '39':
     name: Ground
@@ -360,9 +363,9 @@ pins:
       wiringpi: 29
       bcm: 21
     functions:
-      alt0: PCM_DOUT
-      alt1: SD13
-      alt2: Reserved
-      alt3: BSCSL / CE_N
-      alt4: SPI1_SCLK
+      alt0: PCM DOUT
+      alt1: SMI SD13
+      alt2: DPI Red 7
+      alt3: BSCSL CE
+      alt4: SPI1 SCLK
       alt5: GPCLK1
diff --git a/src/en/settings.yaml b/src/en/settings.yaml
index 5c1b16c..40df19c 100644
--- a/src/en/settings.yaml
+++ b/src/en/settings.yaml
@@ -68,4 +68,5 @@ overlays:
 - iface-gpclk
 - iface-dpi
 - iface-pcm
-- iface-sd
\ No newline at end of file
+- iface-sd
+- iface-jtag
\ No newline at end of file