// 74HC595 wired in "non latching mode" for SR 3 wire operation
// 
//                         74HC595    (VCC)
//                       +----u----+    |
// (LCD RS)------------1-|Q1    VCC|-16-+
// (LCD D4)------------2-|Q2     Q0|-15-------------(BL circuit)
// (LCD D5)------------3-|Q3    SER|-14-------------(data pin)
// (LCD D6)------------4-|Q4    /OE|-13--(gnd)
// (LCD D7)------------5-|Q5   RCLK|-12-------+
//                       |         |          |
//                     6-|Q6   SCLK|-11-------+-----(clock pin)
//                     7-|Q7    /MR|-10--(VCC)
//                   +-8-|GND   Q6'|--9
//                   |   +---------+
//                   |      0.1uf
//                 (gnd)-----||----(VCC)
// 
// (enable pin)-----------------------------------(LCD Enable)
//
// (LCD RW)--(gnd)
//
// ---------------------------------------------------------------------------
//
// 74HC595 wired in "latching mode" for SR 3 wire operation
//
// NOTE: pin 11 is not connected to pin 12
//
//                         74HC595    (VCC)
//                       +----u----+    |
// (BL circuit)--------1-|Q1    VCC|-16-+
// (LCD RS)------------2-|Q2     Q0|-15
// (LCD D4)------------3-|Q3    SER|-14-------------(data pin)
// (LCD D5)------------4-|Q4    /OE|-13--(gnd)
// (LCD D6)------------5-|Q5   RCLK|-12--------+
//                       |         |            \
// (LCD D7)------------6-|Q6   SCLK|-11----------)--(clock pin)
//                     7-|Q7    /MR|-10--(VCC)  /
//                   +-8-|GND   Q6'|--9         |
//                   |   +---------+            |
//                   |      0.1uf               |
//                 (gnd)-----||----(VCC)        |
//                                              |
// (enable pin)---------------------------------+-(LCD Enable)
//
// (LCD RW)--(gnd)            





   *                         74HC595    (VCC)
   *                       +----U----+    |
   * (LCD D1)------------1-|Q1    VCC|-16-+
   * (LCD D2)------------2-|Q2     Q0|-15-----------(LCD D0)
   * (LCD D3)------------3-|Q3    /OE|-13-----------(GND)  
   * (LCD D4)------------4-|Q4    SER|-14-----------(SDA)
   * (LCD D5)------------5-|Q5   RCLK|-12-----------(EN)
   * (LCD D6)------------6-|Q6   SCLK|-11-----------(SCL)
   * (LCD D7)------------7-|Q7    /MR|-10-----------(VCC)
   *                   +-8-|GND   Q6'|-9
   *                   |   +---------+
   *                   |      0.1uF
   *                 (GND)-----||----(VCC)
   * (LCD RS)---------------------------------------(SDA)
   * (LCD EN)---------------------------------------(EN)
   * (LCD BT)---------------------------------------(BT)
   * (LCD RW)---------------------------------------(GND)


void 
HD44780::SR4W::write8b(uint8_t data)
{
  m_sda.write(data, m_scl);
  m_sda.write(m_rs);
  m_en.toggle();
  m_en.toggle();
  DELAY(SHORT_EXEC_TIME);
}