sravan/system76-embedded-controller
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Only drive wait line low in peripheral

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This commit is contained in:
Jeremy Soller 2020-01-02 09:12:44 -07:00
parent e79620989f
commit 49bde8176f
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GPG Key ID: E988B49EE78A7FB1
1 changed files with 5 additions and 7 deletions
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12
src/board/arduino/mega2560/parallel.c
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@ -245,14 +245,14 @@ void parallel_peripheral(void) {
struct Parallel * port = &PORT;
parallel_hiz(port);
// Set wait line to low output
gpio_set_dir(port->wait_n, true);
// Strobes are high when inactive
bool last_data_n = true;
bool last_addr_n = true;
for (;;) {
// Pull wait line low
gpio_set_dir(port->wait_n, true);
// Read data strobe and edge detect
bool data_n = gpio_get(port->data_n);
bool data_edge = last_data_n && !data_n;
@ -277,8 +277,8 @@ void parallel_peripheral(void) {
//TODO: Check if strobe fell while reading
// Set wait line high
gpio_set(port->wait_n, true);
// Release wait line
gpio_set_dir(port->wait_n, false);
if (data_edge) {
putchar('d');
@ -299,8 +299,6 @@ void parallel_peripheral(void) {
// Delay 5 usecs
_delay_us(5);
// Set wait line low
gpio_set(port->wait_n, false);
}
}