STM32-H152

STM32-H152 development board Users Manual All boards produced by Olimex are ROHS compliant Revision Initial, September 2011 Copyright(c) 2011, OLIMEX Ltd, All rights reserved Page 1 INTRODUCTION: STM32-H152 is header board with STM32L152VBT6 ARM Cortex M3 microcontroller from STMicroelectronics. This microcontroller supports various communication interfaces such as USB, three USARTs, two SPIs, two I2C. There are available mini USB, JTAG and UEXT connectors, two buttons – WKUP and RESET, two status leds and extension connectors for most of the microcontroller's pins. All this allows you to build a different projects to be used in a wide range of applications. BOARD FEATURES: • MCU: STM32L152VBT6 – 128 KB Flash, 16 KB Data RAM • Mini USB • 3.7V-LI_BAT connector • Battery charger • JTAG connector • UEXT connector • Two status leds • Reset circuit • RESET button • WKUP button • Extension connectors for most of the microcontroller pins • FR-4, 1.5 mm, soldermask, component print • Dimensions: 70.00 x 50.00 mm (2.76 x 1.97") Page 2 ELECTROSTATIC WARNING: The STM32-H152 board is shipped in protective anti-static packaging. The board must not be subject to high electrostatic potentials. General practice for working with static sensitive devices should be applied when working with this board. BOARD USE REQUIREMENTS: Cables: The cable you will need depends on the programmer/debugger you use. If you use ARM-JTAG-EW, ARM-USB-TINY or ARM-USB-TINY-H, you will need USB A-B cable, if you use ARM-USB-OCD or ARM-USB-OCD-H, you will need USB A-B cable and RS232 cable. Hardware: Programmer/Debugger ARM-USB-OCD, ARM-USB-OCD-H, ARM-USB-TINY, ARM-USB-TINY-H, ARM-JTAG-EW or other compatible programming/debugging tool if you work with EW-ARM. PROCESSOR FEATURES: STM32-H152 board use ARM 32-bit Cortex™-M3 microcontroller STM32L152VBT6 from STMicroelectronics with these features: − − − − − Operating conditions − Operating power supply range: 1.65 V to 3.6 V (without BOR) or 1.8 V to 3.6 V (with BOR option) − Temperature range: –40 to 85 °C Low power features − 4 modes: Sleep, Low-power run (9 μA at 32 kHz), Low-power sleep (4.4 μA), Stop with RTC (1.45 μA), Stop (570 nA), Standby (300 nA) − Dynamic core voltage scaling down to 233 μA/MHz − Ultralow leakage per I/O: 50 nA − Fast wakeup from Stop: 8 μs − Three wakeup pins Core: ARM 32-bit Cortex™-M3 CPU − 32 MHz maximum frequency, 33.3 DMIPS peak (Dhrystone 2.1) − Memory protection unit Reset and supply management − Low power, ultrasafe BOR (brownout reset) with 5 selectable thresholds − Ultralow power POR/PDR − Programmable voltage detector (PVD) Clock management Page 3 − − 1 to 24 MHz crystal oscillator − 32 kHz oscillator for RTC with calibration − Internal 16 MHz factory-trimmed RC − Internal 37 kHz low consumption RC − Internal multispeed low power RC, 64 kHz to 4 MHz with a consumption down to 1.5 μA − PLL for CPU clock and USB (48 MHz) Low power calendar RTC − − Alarm, periodic wakeup from Stop/Standby Memories − 128 Kbyte of Flash memory with ECC − 4 Kbyte of data EEPROM with ECC − 16 Kbyte of RAM − 83 fast I/Os (73 of which are 5 V-tolerant) all mappable on 16 external interrupt vectors − Development support − Serial wire debug, JTAG and trace − DMA: 7-channel DMA controller, supporting timers, ADC, SPIs, I2Cs and USARTs − LCD 8 × 40 or 4 × 44 with step-up converter − 12-bit ADC up to 1 Msps/24 channels − Temperature sensor and internal voltage reference − Operates down to 1.8 V − 2× 12-bit DACs with output buffers − 2 ultralow power comparators − − − − Window mode and wakeup capability 10 timers: − 6 × 16-bit general-purpose timers, each with up to 4 IC/OC/PWM channels − 2 × 16-bit basic timers − 2 × watchdog timers (independent and window) 8 communication interfaces: − 2 × I2C interfaces (SMBus/PMBus) − 3 × USARTs (ISO 7816 interface, LIN, IrDA capability, modem control) − 2 × SPIs (16 Mbit/s) − USB 2.0 full speed interface CRC calculation unit, 96-bit unique ID Page 4 Page 5 BLOCK DIAGRAM: AF = Alternate Function function on I/O port pin. Page 6 MEMORY MAP: Page 7 C3 100nF Page 8 R6 1 2 3 Q1 B0_ 1/B0_ 0 STAT1 STAT2 SPI1_ NSS SPI1_ SCK SPI1 _MISO SPI1 _MO SI RST +5V_ USB R1 4 4 .7k 1 0k R8 1 uF/10 V HN1 x3 0 C16 CO N2-6 CO N1-6 NA 100 nF C1 3 1u F/1 0V C1 5 C1 4 97 98 1 2 3 4 5 38 39 40 41 42 43 44 45 46 14 73 13 12 94 6 20 21 19 22 STM32L 15 2VBT6 OSC_IN/PD0/SPI2_NSS/TIM9_CH1 OSC_OUT/PD1/SPI2_SCK PD2/TIM3_ETR/LCD_SEG31/LCD_SEG43/LCD_COM7 PD3/USART2_CTS/SPI2_MISO PD4/USART2_RTS/SPI2_MOSI PD5/USART2_TX PD6/USART2_RX PD7/USART2_CK/TIM9_CH2 PD8/USART3_TX/LCD_SEG28 PD9/USART3_RX/LCD_SEG29 PD10/USART3_CK/LCD_SEG30 PD11/USART3_CTS/LCD_SEG31 PD12/TIM4_CH1/USART3_RTS/LCD_SEG32 PD13/TIM4_CH2/LCD_SEG33 PD14/TIM4_CH3/LCD_SEG34 PD15/TIM4_CH4/LCD_SEG35 PC0/ADC_IN10/LCD_SEG18/COMP1_INP PC1/ADC_IN11/LCD_SEG19/COMP1_INP PC2/ADC_IN12/LCD_SEG20/COMP1_INP PC3/ADC_IN13/LCD_SEG21/COMP1_INP PC4/ADC_IN14/LCD_SEG22/COMP1_INP PC5/ADC_IN15/LCD_SEG23/COMP1_INP PC6/TIM3_CH1/LCD_SEG24 PC7/TIM3_CH2/LCD_SEG25 PC8/TIM3_CH3/LCD_SEG26 PC9/TIM3_CH4/LCD_SEG27 PC10/USART3_TX/LCD_SEG28/LCD_SEG40/LCD_COM4 PC11/USART3_RX/LCD_SEG29/LCD_SEG41/LCD_COM5 PC12/USART3_CK/LCD_SEG30/LCD_SEG42/LCD_COM6 PC13/RTC_AF1/WKUP2 PC14/OSC32_IN PC15/OSC32_OUT PB0/ADC_IN8/TIM3_CH3/LCD_SEG5/COMP1_INP/VREF_OUT PB1/ADC_IN9/TIM3_CH4/LCD_SEG6/COMP1_INP/VREF_OUT PB2/BOOT1 JTDO/TIM2_CH2/PB3/TRACESWO/SPI1_SCK/COMP2_INM/LCD_SEG7 JNTRST/TIM3_CH1/PB4/SPI1_MISO/COMP2_INP/LCD_SEG8 PB5/I2C1_SMBAL/TIM3_CH2/SPI1_MOSI/COMP2_INP/LCD_SEG9 PB6/I2C1_SCL/TIM4_CH1/USART1_TX/LCD_SEG8 PB7/I2C1_SDA/TIM4_CH2/USART1_RX/PVD_IN PB8/TIM4_CH3/I2C1_SCL/LCD_SEG16/TIM10_CH1 PB9/TIM4_CH4/I2C1_SDA/LCD_COM3/TIM11_CH1 PB10/I2C2_SCL/USART3_TX/TIM2_CH3/LCD_SEG10 PB11/I2C2_SDA/USART3_RX/TIM2_CH4/LCD_SEG11 PB12/SPI2_NSS/I2C2_SMBA/USART3_CK/LCD_SEG12/ADC_IN18/COMP1_INP/TIM10_CH1 PB13/SPI2_SCK/USART3_CTS/LCD_SEG13/ADC_IN19/COMP1_INP/TIM9_CH1 PB14/SPI2_MISO/USART3_RTS/LCD_SEG14/ADC_IN20/COMP1_INP/TIM9_CH2 PB15/SPI2_MOSI/TIM1_CH3N/LCD_SEG15/ADC_IN21/COMP1_INP/TIM11_CH1/RTC_50_60HZ PA0/WKUP1/USART2_CTS/ADC_IN0/TIM2_CH1_ETR/COMP1_INP PA1/USART2_RTS/ADC_IN1/TIM2_CH2/LCD_SEG0/COMP1_INP PA2/USART2_TX/ADC_IN2/TIM2_CH3/TIM9_CH1/LCD_SEG1/COMP1_INP PA3/USART2_RX/ADC_IN3/TIM2_CH4/TIM9_CH2/LCD_SEG2/COMP1_INP PA4/SPI1_NSS/USART2_CK/ADC_IN4/DAC_OUT1/COMP1_INP PA5/SPI1_SCK/ADC_IN5/DAC_OUT2/TIM2_CH1_ETR/COMP1_INP PA6/SPI1_MISO/ADC_IN6/TIM3_CH1/TIM1_BKIN/LCD_SEG3/TIM10_CH1/COMP1_INP PA7/SPI1_MOSI/ADC_IN7/TIM3_CH2/TIM1_CH1N/LCD_SEG4/TIM11_CH1/COMP1_INP PA8/USART1_CK/MCO/LCD_COM0 PA9/USART1_TX/LCD_COM1 PA10/USART1_RX/LCD_COM2 PA11/USART1_CTS/USBDM/SPI1_MISO PA12/USART1_RTS/USBDP/SPI1_MOSI JTMS/SWDIO/PA13 JTCK/SWCLK/PA14 JTDI/TIM2_CH1_ETR/PA15/SPI1_NSS/LCD_SEG17 PE0/TIM4_ETR/LCD_SEG36/TIM10_CH1 PE1/LCD_SEG37/TIM11_CH1 PE2/TRACECK/LCD_SEG38/TIM3_ETR PE3/TRACED0/LCD_SEG39/TIM3_CH1 PE4/TRACED1/TIM3_CH2 PE5/TRACED2/TIM9_CH1 PE6/TRACED3/WKUP3/TIM9_CH2 PE7/ADC_IN22/COMP1_INP PE8/ADC_IN23/COMP1_INP PE9/ADC_IN24/TIM2_CH1_ETR/COMP1_INP PE10/ADC_IN25/TIM2_CH2/COMP1_INP PE11/TIM2_CH3 PE12/TIM2_CH4/SPI1_NSS PE13/SPI1_SCK PE14/SPI1_MISO PE15/SPI1_MOSI NRST PH2/I2C2_SMBA OSC_OUT/PH1 OSC_IN/PH0 BOOT0 VLCD VREF- VREF+ VSSA VDDA VSS_5 VSS_4 VSS_3 VSS_2 VSS_1 VDD_1 VDD_2 VDD_3 VDD_4 VDD_5 R3 4 1 0k 81 82 83 84 85 86 87 88 55 56 57 58 59 60 61 62 15 16 17 18 33 34 63 64 65 66 78 79 80 7 8 9 35 36 37 89 90 91 92 93 95 96 47 48 51 52 53 54 USART2 _TX USART2 _RX R1 7 CO N2 -2 0 CO N2 -21 CO N2-22 CO N2-23 CO N2-2 4 CO N2-2 5 CO N2 -2 6 CO N2 -2 7 CO N2 -28 CO N2 -29 CO N2-30 CO N2 -18 CO N2-19 G ND TMS/SW DIO TCK/SW CLK CO N2-10 CO N2-1 1 CO N2-1 2 CO N2 -1 3 CO N2 -14 CO N2 -15 CO N2 -16 CO N2-17 3.3V CO N1 -3 6 CO N1 -35 HN2 X40 CO N1 -34 CO N1-33 CO N1-32 CO N1-3 1 CO N1 -3 0 CO N1 -2 9 CO N1 -2 8 CO N1 -27 CO N1-26 CO N1-25 CO N1-2 4 CO N1-2 3 CO N1 -2 2 CO N1 -21 GND 1 2 CLO SE G NDA_ E SPI1 _MO SI SPI1 _MISO SPI1 _SCK SPI1 _NSS USART2_ TX USART2 _RX I2 C1 _SCL I2 C1 _SDA TRST TDO TRST TDI TMS/SW DIO TCK/SW CLK R21 33 k 3 .3V C6 R22 4.7 k RST R-T R2 R3 R3 1 22 R 2 2R 3 30 R 2 R9 NA NA R1 1 NA USART2_ RX I2C1_ SDA SPI1_ MO SI SPI1_ NSS 2 4 6 8 10 1 3 5 7 9 BH10 S UEXT 1 2 3 1 0k 1 0k 10 k R1 3 NA R20 4 .7k 3 .3V USART2 _TX I2C1_ SCL SPI1_ MISO SPI1 _SCK 3 .3V R18 R19 R1 6 R1 2 NA C9 1 00 nF U4 R2 8 10 k BH2 0S JTAG 2 4 6 8 10 12 14 16 18 20 3.3 V 1M 1 00 nF 10 0n F C26 3 30 R R32 1 00 R/1 % R30 3 .3 V RST STAT1 RED(GYX-SD-TC0805SYRK) STAT1 R26 3 30 R STAT2 GREEN(GYX-SD-TC0805SGC) STAT2 3.3V R27 3 30 R 3.3V STATUS LEDS 1 3 5 7 9 11 13 15 17 19 R4 VBUS DD+ ID GND USB USB_MINI RESET C10 GND NA(S TM1001RW X 6F) 2 VCC RESET 1 +5 V_USB +5 V_JTAG JTAG USBL C6 -2 P6(NA) 6 5 4 U1 10 0n F C8 3.3 V USB CIRCUIT W KUP UEXT R1 5 R1 0 NA 47p F(NA) C7 C2 5 1 00 nF R29 1 00R/1 % R3 3 10 0k O PEN 1 4 7pF(NA) USB_DP USB_DM W KUP SPI1 _SCK,SPI1 _MO SI,SPI1 _MISO ,SPI1_NSS,I2C1_ SDA,I2C1_ SCL,USART2_ RX,USART2_ TX USART2_ RX I2 C1 _SDA SPI1_ MO SI SPI1_ NSS TDO TRST TDI TMS/SW DIO ,TCK/SW CLK,TRST,TDO ,TDI CO N2 -9 CO N2-8 USB_DP,USB_DM 1 C21 2 .2u F/6.3 V CO N2-3 1 CO N2-3 2 CO N2 -3 3 CO N2-3 4 CO N2-3 5 CO N2 -3 6 CO N2 -3 7 CO N2 -38 CO N2 -39 CO N2-40 CO N1 -4 0 CO N1 -39 CO N1 -38 CO N1-37 C1 9 10p F Q2 NA C20 1 0p F 3 27 68 Hz/6pF I2C1_ SCL I2C1_ SDA PB2 /BO O T1 TDO TRST 23 W KUP 24 BATTERY_VOLTAGE 25 ENABLE_MEASUREMENT 26 29 30 31 32 67 68 69 USB_DM 70 USB_ DP 71 72 TMS/SW DIO TCK/SW CL K 76 77 TDI ENABLE_MEASUREMENT C2 7 1 00 nF BATTERY_VOLTAGE 3 .7V-L I_ BAT DW 0 2R - 1 2 C22 2 .2u F/6 .3 V RESET CIRCUIT GND4 GND3 CO N1 -17 CO N1 -18 CO N1-19 CO N1-2 0 CO N1-7 CO N1-8 CO N1-9 CO N1 -1 0 CO N1 -1 1 CO N1 -12 CO N1 -13 CO N1-14 CO N1-15 CO N1-1 6 C18 2 7p F C1 2 10 0n F CO N1 -5 CO N2-5 1 2 3 Q8.000MHz/HC-49SM(SMD)/20pF C1 7 27 pF 0R(NA) 3.3V 0R CO N1 -4 CO N2 -4 R5 0R 0 R(NA) C1 1 1u F/1 0V 10 27 99 74 49 50 75 100 28 11 U2 2.2 uF/6 .3V C24 R24 3 3k IRLM L6402 FET1 3 3 .3 V BUTTONS 3 B1_ 1/B1 _0 HN1x3 C1 100nF 1 0k C2 2.2uF/6.3V CO N1-3 FB1 CO N2-3 C4 100nF 0 CL O SE C5 100nF FB0805/600R/200mA(201209-601) 1 SHUNT_E 2 3.3 V 5 1 R23 4.7k VIN VOUT 3.3 V USB PB2/BO O T1 CO N2 -2 CO N1-2 1R R1 +5V 3 2 M CP1702T -3302E/MB VR(3 .3V) GND2 GND1 R7 2 1 15 k VSSPROG appr. 70 mA charge current R2 5 2 BATTERY CE CHARGER VDDVBAT D3 BAT54 C IT1185AU2 3 .3 V 3 .3V_ MCU_ E HN1 x2 C23 4 M CP73812T-420I/OT U3 Battery Charger D1 BAT54 C POWER SUPPLY CIRCUIT +5 V 2 .2 uF/6.3V D2 BAT54 C CO N2-7 5 -6VDC + CO N2 -1 +5V_ JTAG +5 V_USB IT 118 5AU2 CO N1 -1 HN2 X4 0 h ttp ://www.olimex.co m/d ev CO PYRIG HT(C) 201 1, O L IMEX L td . Re v. B STM32-H152 SCHEMATIC: BOARD LAYOUT: Page 9 POWER SUPPLY CIRCUIT: STM32-H152 can take power from: –USB - +5V_USB. –J-link - +5V_JTAG. –Battery connector – +3.7V lithium battery. –Extension connector CON2 pin 7 (VIN) – (5÷6) VDC. The programmed board power consumption is about 30 mA. Note that if the battery is connected to 3,7V-Li BAT connector and some of other power sources(USB, JTAG, CON2 pin 7 (VIN)) are present and the battery is discharged then the battery will be charged until the charge complete. RESET CIRCUIT: STM32-H152 reset circuit includes R28 (10k), R30 (330Ω), R32 (100Ω/1%), C26 (100nF), STM32L152VBT6 pin 14 (NRST) and RESET button. CLOCK CIRCUIT: Quartz crystal (Q1) 8 MHz is connected to STM32L152VBT6 pin 12 (OSC_IN/PH0) and pin 13 (OSC_OUT/PH1). Quartz crystal (Q2) 32.768 kHz is connected to STM32L152VBT6 pin 8 (PC14/OSC32_IN) and pin 9 (PC15/OSC32_OUT). JUMPER DESCRIPTION: R-T When this jumper is closed, RST and TRST are connected. When this jumper is opened, RST and TRST are separated. Default state is opened. SHUNT_E When this jumper is closed, 1 Ohm shunt is enabled. When this jumper is opened, 1 Ohm shunt is disabled. Default state is closed. GNDA_E When this jumper is closed, the board analog ground is enabled. When this jumper is opened, the board analog ground is disabled. Default state is closed. 3.3V_MCU_E When this jumper is closed, STM32L152VBT6 power supply is enabled. When this jumper is opened, STM32L152VBT6 power supply is disabled. Default state is closed. Page 10 B0_1/B0_0 This jumper, when is in position B0_1 – connects STM32L152VBT6 pin 94 (BOOT0) via R8 (10k) to 3.3V, when the jumper is in position B0_0 – connects STM32L152VBT6 pin 94 (BOOT0) via R8 (10k) to GND. Default state is closed in position B0_0. B1_1/B1_0 This jumper, when is in position B1_1 – connects STM32L152VBT6 pin 37 (PB2/BOOT1) via R7 (10k) to 3.3V, when the jumper is in position B1_0 – connects STM32L152VBT6 pin 37 (PB2/BOOT1) via R7 (10k) to GND. Default state is closed in position B1_0. - B1_1 The boot mode is selected depending on jumpers B0_1/B0_0 and B1_1/B1_0 configuration: - When B0_1/B0_0 is closed in position B0_0 and B1_1/B1_0 position doesn't matter the boot mode is Main Flash Memory. - When B0_1/B0_0 is closed in position B0_1 and B1_1/B1_0 is closed in position B1_0 – the boot mode is System Memory. - When B0_1/B0_0 is closed in position B0_1 and B1_1/B1_0 is closed in position – the boot mode is Embedded SRAM. INPUT/OUTPUT: Status led (red), with name STAT1 is connected to STM32L152VBT6 pin 41 (PF10). Status led (green), with name STAT2 is connected to STM32L152VBT6 pin 42 (PF11). User button with name WKUP is connected to STM32L152VBT6 pin 23 (PA0/WKUP1). User button with name RESET is connected to STM32L152VBT6 pin 14 (NRST). Page 11 EXTERNAL CONNECTORS DESCRIPTION: UEXT: Pin # Signal Name 1 VCC (3.3V) 2 GND 3 USART2_TX 4 USART2_RX 5 I2C1_SCL 6 I2C1_SDA 7 SPI1_MISO 8 SPI1_MOSI 9 SPI1_SCK 10 SPI1_NSS USB: Pin # Signal Name 1 +5V_USB 2 USB_DM 3 USB_DP 4 Not Connected 5 GND Page 12 3.7V-LI_BAT: Pin # Signal Name 1 VBAT 2 GND JTAG: Pin # Signal Name Pin # Signal Name 1 VCC (3.3V) 2 VCC (3.3V) 3 TRST 4 GND 5 TDI 6 GND 7 TMS/SWDIO 8 GND 9 TCK/SWCLK 10 GND 11 Via 10k to GND 12 GND 13 TDO 14 GND 15 RST 16 GND 17 Via 10k to GND 18 GND 19 +5V_JTAG 20 GND Page 13 CON1: Pin # Signal Name Pin # Signal Name 1 VCC (3.3V) 2 GND 3 VDDA 4 AGND 5 VREF+ 6 VREF- 7 PE0 8 PE1 9 PE2 10 PE3 11 PE4 12 PE5 13 PE6 14 PE7 15 PE8 16 PE9 17 SPI1_NSS 18 SPI1_SCK 19 SPI1_MISO 20 SPI1_MOSI 21 PD15 22 PD14 23 PD13 24 PD12 25 PD11 26 PD10 27 PD9 28 PD8 29 PD7 30 USART2_RX 31 USART2_TX 32 PD4 33 PD3 34 PD2 35 PD1 36 PD0 37 PC13 38 PC12 39 PC11 40 PC10 Page 14 CON2: Pin # Signal Name Pin # Signal Name 1 VCC (3.3V) 2 GND 3 VDDA 4 AGND 5 VREF+ 6 VREF- 7 VIN 8 GND 9 VCC (3.3V) 10 PA3 11 PA4 12 PA5 13 PA6 14 PA7 15 PA8 16 PA9 17 PA10 18 PB0 19 PB1 20 PB5 21 I2C1_SCL 22 I2C1_SDA 23 PB8 24 PB9 25 PB10 26 PB11 27 PB12 28 PB13 29 PB14 30 PB15 31 PC0 32 PC1 33 PC2 34 PC3 35 PC4 36 PC5 37 PC6 38 PC7 39 PC8 40 PC9 Page 15 MECHANICAL DIMENSIONS: Page 16 AVAILABLE DEMO SOFTWARE:  Demo software USB mouse and Blinking LED for EW-ARM  Setup GCC+Eclispse for STM32 on MAC Page 17 ORDER CODE: STM32-H152 - assembled and tested board How to order? You can order to us directly or by any of our distributors. Check our web www.olimex.com/dev for more info. Revision history: Boar's revision: Rev. B, June 2011 Manual's revision: Rev. Initial, September 2011 Page 18 Disclaimer: © 2011 Olimex Ltd. All rights reserved. Olimex®, logo and combinations thereof, are registered trademarks of Olimex Ltd. Other terms and product names may be trademarks of others. The information in this document is provided in connection with Olimex products. No license, express or implied or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Olimex products. Neither the whole nor any part of the information contained in or the product described in this document may be adapted or reproduced in any material from except with the prior written permission of the copyright holder. The product described in this document is subject to continuous development and improvements. All particulars of the product and its use contained in this document are given by OLIMEX in good faith. However all warranties implied or expressed including but not limited to implied warranties of merchantability or fitness for purpose are excluded. This document is intended only to assist the reader in the use of the product. OLIMEX Ltd. shall not be liable for any loss or damage arising from the use of any information in this document or any error or omission in such information or any incorrect use of the product. Page 19